DFU fails with "Cannot read property 'instanceId' of undefined"

running DFU example from <SDK 15.3>\examples\dfu\secure_dfu_test_images\ble\nrf52840, and attempting a DFU update of:

sd_s140_bootloader_buttonless_with_setting_page_dfu_secure_ble_debug_without_bonds.hex

to

hrs_application_s140.zip.

The DFU is performed on the nRF52840 DK, using this procedure:

  1. I burn the .hex image via the J-Link drive on a Windows PC, by copying it there.
  2. I connect to the device via nRF-Connect on the Windows PC, and start the DFU process, selecting the .zip image.

Mostly, the DFU is successful, and Nordic_HRM becomes the device' name.

Sometimes, the DFU fails with "Cannot read property 'instanceId' of undefined".

I have the failure logs, of both the RTT log of the device 

# SEGGER J-Link RTT Viewer V6.44f Terminal Log File
# Compiled: 17:18:21 on Apr 12 2019
# Logging started @ 17 Apr 2019 15:14:31

 

 
<00> info> app: Inside main
00> 
<00> debug> app: In nrf_bootloader_init
00> 
<00> debug> nrf_dfu_settings: Calling nrf_dfu_settings_init()...
00> 
<00> debug> nrf_dfu_flash: Initializing nrf_fstorage_nvmc backend.
00> 
<00> debug> nrf_dfu_settings: Using settings page.
00> 
<00> debug> nrf_dfu_settings: Copying forbidden parts from backup page.
00> 
<00> debug> nrf_dfu_settings: Destination settings are identical to source, write not needed. Skipping.
00> 
<00> info> nrf_dfu_settings: Backing up settings page to address 0xFE000.
00> 
<00> debug> nrf_dfu_settings: Destination settings are identical to source, write not needed. Skipping.
00> 
<00> debug> app: Enter nrf_bootloader_fw_activate
00> 
<00> info> app: No firmware to activate.
00> 
<00> debug> app: App is valid
00> 
<00> info> nrf_dfu_settings: Backing up settings page to address 0xFE000.
00> 
<00> debug> nrf_dfu_settings: Destination settings are identical to source, write not needed. Skipping.
00> 
<00> debug> app: Running nrf_bootloader_app_start with address: 0x00001000
00> 
<00> debug> app: Disabling interrupts. NVIC->ICER[0]: 0x0
00> 

 
<00> info> app: Inside main
00> 
<00> debug> app: In nrf_bootloader_init
00> 
<00> debug> nrf_dfu_settings: Calling nrf_dfu_settings_init()...
00> 
<00> debug> nrf_dfu_flash: Initializing nrf_fstorage_nvmc backend.
00> 
<00> info> nrf_dfu_settings: Restoring settings from backup since the settings page contents are invalid (CRC error).
00> 
<00> info> nrf_dfu_settings: Old settings page detected. Upgrading info.
00> 
<00> debug> nrf_dfu_settings: Writing settings...
00> 
<00> debug> nrf_dfu_settings: Erasing old settings at: 0x000FF000
00> 
<00> debug> nrf_dfu_flash: nrf_fstorage_erase(addr=0x0x000FF000, len=1 pages), queue usage: 0
00> 
<00> debug> nrf_dfu_flash: Flash erase success: addr=0x000FF000, pending 0
00> 
<00> debug> nrf_dfu_flash: nrf_fstorage_write(addr=0x000FF000, src=0x20007D90, len=896 bytes), queue usage: 1
00> 
<00> debug> nrf_dfu_flash: Flash write success: addr=0x000FF000, pending 0
00> 
<00> info> nrf_dfu_settings: Backing up settings page to address 0xFE000.
00> 
<00> debug> nrf_dfu_settings: Writing settings...
00> 
<00> debug> nrf_dfu_settings: Erasing old settings at: 0x000FE000
00> 
<00> debug> nrf_dfu_flash: nrf_fstorage_erase(addr=0x0x000FE000, len=1 pages), queue usage: 1
00> 
<00> debug> nrf_dfu_flash: Flash erase success: addr=0x000FE000, pending 0
00> 
<00> debug> nrf_dfu_flash: nrf_fstorage_write(addr=0x000FE000, src=0x20008110, len=896 bytes), queue usage: 1
00> 
<00> debug> nrf_dfu_flash: Flash write success: addr=0x000FE000, pending 0
00> 
<00> debug> app: Enter nrf_bootloader_fw_activate
00> 
<00> info> app: No firmware to activate.
00> 
<00> debug> app: App is valid
00> 
<00> info> nrf_dfu_settings: Backing up settings page to address 0xFE000.
00> 
<00> debug> nrf_dfu_settings: Destination settings are identical to source, write not needed. Skipping.
00> 
<00> debug> app: Running nrf_bootloader_app_start with address: 0x00001000
00> 
<00> debug> app: Disabling interrupts. NVIC->ICER[0]: 0x0
00> 
<00> info> app: Inside main
00> 
<00> debug> app: In nrf_bootloader_init
00> 
<00> debug> nrf_dfu_settings: Calling nrf_dfu_settings_init()...
00> 
<00> debug> nrf_dfu_flash: Initializing nrf_fstorage_nvmc backend.
00> 
<00> debug> nrf_dfu_settings: Using settings page.
00> 
<00> debug> nrf_dfu_settings: Copying forbidden parts from backup page.
00> 
<00> debug> nrf_dfu_settings: Destination settings are identical to source, write not needed. Skipping.
00> 
<00> info> nrf_dfu_settings: Backing up settings page to address 0xFE000.
00> 
<00> debug> nrf_dfu_settings: Destination settings are identical to source, write not needed. Skipping.
00> 
<00> debug> app: Enter nrf_bootloader_fw_activate
00> 
<00> info> app: No firmware to activate.
00> 
<00> debug> app: App is valid
00> 
<00> info> nrf_dfu_settings: Backing up settings page to address 0xFE000.
00> 
<00> debug> nrf_dfu_settings: Destination settings are identical to source, write not needed. Skipping.
00> 
<00> debug> app: Running nrf_bootloader_app_start with address: 0x00001000
00> 
<00> debug> app: Disabling interrupts. NVIC->ICER[0]: 0x0
00> 

 
<00> info> app: Inside main
00> 
<00> debug> app: In nrf_bootloader_init
00> 
<00> debug> nrf_dfu_settings: Calling nrf_dfu_settings_init()...
00> 
<00> debug> nrf_dfu_flash: Initializing nrf_fstorage_nvmc backend.
00> 
<00> debug> nrf_dfu_settings: Using settings page.
00> 
<00> debug> nrf_dfu_settings: Copying forbidden parts from backup page.
00> 
<00> debug> nrf_dfu_settings: Destination settings are identical to source, write not needed. Skipping.
00> 
<00> info> nrf_dfu_settings: Backing up settings page to address 0xFE000.
00> 
<00> debug> nrf_dfu_settings: Destination settings are identical to source, write not needed. Skipping.
00> 
<00> debug> app: Enter nrf_bootloader_fw_activate
00> 
<00> info> app: No firmware to activate.
00> 
<00> debug> app: App is valid
00> 
<00> debug> app: DFU mode requested via GPREGRET.
00> 
<00> info> nrf_bootloader_wdt: WDT is not enabled
00> 
<00> debug> app: in weak nrf_dfu_init_user
00> 
<00> debug> app: timer_stop (0x200057D4)
00> 
<00> debug> app: timer_activate (0x200057D4)
00> 
<00> info> app: Entering DFU mode.
00> 
<00> debug> app: Initializing transports (found: 1)
00> 
<00> debug> nrf_dfu_ble: Initializing BLE DFU transport
00> 
<00> debug> nrf_dfu_ble: Setting up vector table: 0x000F1000
00> 
<00> debug> nrf_dfu_ble: Enabling SoftDevice.
00> 
<00> debug> nrf_dfu_ble: Configuring BLE stack.
00> 
<00> debug> nrf_dfu_ble: Enabling the BLE stack.
00> 
<00> debug> nrf_dfu_ble: No advertising name found
00> 
<00> debug> nrf_dfu_ble: Using default advertising name
00> 
<00> debug> nrf_dfu_ble: Advertising...
00> 
<00> debug> nrf_dfu_ble: BLE DFU transport initialized.
00> 
<00> debug> nrf_dfu_flash: Initializing nrf_fstorage_sd backend.
00> 
<00> debug> app: Enter main loop
00> 

# Logging stopped @ 17 Apr 2019 15:24:16

and the nRF Connect log:

2019-04-17T12:22:50.770Z DEBUG 10061/ 0 <-  [02 32 00 00 00 0a 01 10 00 00 00 ]
               type:     VENDOR_SPECIFIC reliable:yes seq#:0 ack#:7 payload_length:b data_integrity:1 header_checksum:4a err_code:0
2019-04-17T12:22:50.770Z DEBUG    10063 ->  []
               type:                 ACK reliable: no seq#:0 ack#:1 payload_length:0 data_integrity:0 err_code:0
2019-04-17T12:22:50.770Z DEBUG GATTC_EVT_CHAR_DISC_RSP time:2019-04-17T12:22:50.771Z connHandle:0 gattStatus:266 gattStatusName:atterrAttributeNotFound errorHandle:16 count:0 chars:[]
2019-04-17T12:22:50.771Z DEBUG    10064 ->  [00 97 00 00 01 11 00 ff ff ]
               type:     VENDOR_SPECIFIC reliable:yes seq#:7 ack#:1 payload_length:9 data_integrity:1 header_checksum:93 err_code:0
2019-04-17T12:22:50.774Z DEBUG 10062/ 0 <-  []
               type:                 ACK reliable: no seq#:0 ack#:0 payload_length:0 data_integrity:0 err_code:0
2019-04-17T12:22:50.774Z DEBUG 10063/ 0 <-  [01 97 00 00 00 00 ]
               type:     VENDOR_SPECIFIC reliable:yes seq#:1 ack#:0 payload_length:6 data_integrity:1 header_checksum:d1 err_code:0
2019-04-17T12:22:50.774Z DEBUG    10065 ->  []
               type:                 ACK reliable: no seq#:0 ack#:2 payload_length:0 data_integrity:0 err_code:0
2019-04-17T12:22:50.972Z DEBUG 10064/ 0 <-  [02 33 00 00 00 00 00 00 00 01 00 11 00 02 29 01 ]
               type:     VENDOR_SPECIFIC reliable:yes seq#:2 ack#:0 payload_length:10 data_integrity:1 header_checksum:2f err_code:0
2019-04-17T12:22:50.972Z DEBUG    10066 ->  []
               type:                 ACK reliable: no seq#:0 ack#:3 payload_length:0 data_integrity:0 err_code:0
2019-04-17T12:22:50.972Z DEBUG GATTC_EVT_DESC_DISC_RSP time:2019-04-17T12:22:50.972Z connHandle:0 gattStatus:0 gattStatusName:success errorHandle:0 count:1 descs:[[handle:17,uuid:[uuid:10498 type:1 typeString:bleUuidTypeBle]]]
2019-04-17T12:22:50.973Z DEBUG    10067 ->  [00 97 00 00 01 12 00 ff ff ]
               type:     VENDOR_SPECIFIC reliable:yes seq#:0 ack#:3 payload_length:9 data_integrity:1 header_checksum:8a err_code:0
2019-04-17T12:22:50.976Z DEBUG 10065/ 0 <-  []
               type:                 ACK reliable: no seq#:0 ack#:1 payload_length:0 data_integrity:0 err_code:0
2019-04-17T12:22:50.976Z DEBUG 10066/ 0 <-  [01 97 00 00 00 00 ]
               type:     VENDOR_SPECIFIC reliable:yes seq#:3 ack#:1 payload_length:6 data_integrity:1 header_checksum:c7 err_code:0
2019-04-17T12:22:50.976Z DEBUG    10068 ->  []
               type:                 ACK reliable: no seq#:0 ack#:4 payload_length:0 data_integrity:0 err_code:0
2019-04-17T12:22:51.170Z DEBUG 10067/ 0 <-  [02 33 00 00 00 0a 01 12 00 00 00 ]
               type:     VENDOR_SPECIFIC reliable:yes seq#:4 ack#:1 payload_length:b data_integrity:1 header_checksum:76 err_code:0
2019-04-17T12:22:51.170Z DEBUG    10069 ->  []
               type:                 ACK reliable: no seq#:0 ack#:5 payload_length:0 data_integrity:0 err_code:0
2019-04-17T12:22:51.170Z DEBUG GATTC_EVT_DESC_DISC_RSP time:2019-04-17T12:22:51.171Z connHandle:0 gattStatus:266 gattStatusName:atterrAttributeNotFound errorHandle:18 count:0 descs:[]
2019-04-17T12:22:51.171Z DEBUG    10070 ->  [00 9a 00 00 11 00 00 00 ]
               type:     VENDOR_SPECIFIC reliable:yes seq#:1 ack#:5 payload_length:8 data_integrity:1 header_checksum:89 err_code:0
2019-04-17T12:22:51.174Z DEBUG 10068/ 0 <-  []
               type:                 ACK reliable: no seq#:0 ack#:2 payload_length:0 data_integrity:0 err_code:0
2019-04-17T12:22:51.174Z DEBUG 10069/ 0 <-  [01 9a 00 00 00 00 ]
               type:     VENDOR_SPECIFIC reliable:yes seq#:5 ack#:2 payload_length:6 data_integrity:1 header_checksum:bd err_code:0
2019-04-17T12:22:51.174Z DEBUG    10071 ->  []
               type:                 ACK reliable: no seq#:0 ack#:6 payload_length:0 data_integrity:0 err_code:0
2019-04-17T12:22:51.371Z DEBUG 10070/ 0 <-  [02 36 00 00 00 00 00 00 00 11 00 00 00 02 00 00 00 ]
               type:     VENDOR_SPECIFIC reliable:yes seq#:6 ack#:2 payload_length:11 data_integrity:1 header_checksum:b err_code:0
2019-04-17T12:22:51.371Z DEBUG    10072 ->  []
               type:                 ACK reliable: no seq#:0 ack#:7 payload_length:0 data_integrity:0 err_code:0
2019-04-17T12:22:51.371Z DEBUG GATTC_EVT_READ_RSP time:2019-04-17T12:22:51.371Z connHandle:0 gattStatus:0 gattStatusName:success errorHandle:0 handle:17 offset:0 len:2
2019-04-17T12:22:51.371Z DEBUG findCharacteristic: Did not find characteristic ID. Error Error: Unable to find characteristic 8EC90004F3154F609FB8838830DAEA50 for service FE59 on device D4:D5:F6:7C:B1:8C.0
2019-04-17T12:22:51.372Z DEBUG    10073 ->  [00 97 00 00 01 04 00 09 00 ]
               type:     VENDOR_SPECIFIC reliable:yes seq#:2 ack#:7 payload_length:9 data_integrity:1 header_checksum:68 err_code:0
2019-04-17T12:22:51.375Z DEBUG 10071/ 0 <-  []
               type:                 ACK reliable: no seq#:0 ack#:3 payload_length:0 data_integrity:0 err_code:0
2019-04-17T12:22:51.375Z DEBUG 10072/ 0 <-  [01 97 00 00 00 00 ]
               type:     VENDOR_SPECIFIC reliable:yes seq#:7 ack#:3 payload_length:6 data_integrity:1 header_checksum:b3 err_code:0
2019-04-17T12:22:51.375Z DEBUG    10074 ->  []
               type:                 ACK reliable: no seq#:0 ack#:0 payload_length:0 data_integrity:0 err_code:0
2019-04-17T12:22:51.572Z DEBUG 10073/ 0 <-  [02 33 00 00 00 00 00 00 00 05 00 04 00 03 28 01 05 00 01 2a 01 06 00 03 28 01 07 00 04 2a 01 08 00 03 28 01 ]
               type:     VENDOR_SPECIFIC reliable:yes seq#:0 ack#:3 payload_length:24 data_integrity:1 header_checksum:d8 err_code:0
2019-04-17T12:22:51.572Z DEBUG    10075 ->  []
               type:                 ACK reliable: no seq#:0 ack#:1 payload_length:0 data_integrity:0 err_code:0
2019-04-17T12:22:51.572Z DEBUG GATTC_EVT_DESC_DISC_RSP time:2019-04-17T12:22:51.573Z connHandle:0 gattStatus:0 gattStatusName:success errorHandle:0 count:5 descs:[[handle:4,uuid:[uuid:10243 type:1 typeString:bleUuidTypeBle]],[handle:5,uuid:[uuid:10753 type:1 typeString:bleUuidTypeBle]],[handle:6,uuid:[uuid:10243 type:1 typeString:bleUuidTypeBle]],[handle:7,uuid:[uuid:10756 type:1 typeString:bleUuidTypeBle]],[handle:8,uuid:[uuid:10243 type:1 typeString:bleUuidTypeBle]]]
2019-04-17T12:22:51.573Z DEBUG    10076 ->  [00 97 00 00 01 06 00 09 00 ]
               type:     VENDOR_SPECIFIC reliable:yes seq#:3 ack#:1 payload_length:9 data_integrity:1 header_checksum:97 err_code:0
2019-04-17T12:22:51.575Z DEBUG 10074/ 0 <-  []
               type:                 ACK reliable: no seq#:0 ack#:4 payload_length:0 data_integrity:0 err_code:0
2019-04-17T12:22:51.575Z DEBUG 10075/ 0 <-  [01 97 00 00 00 00 ]
               type:     VENDOR_SPECIFIC reliable:yes seq#:1 ack#:4 payload_length:6 data_integrity:1 header_checksum:b1 err_code:0
2019-04-17T12:22:51.575Z DEBUG    10077 ->  []
               type:                 ACK reliable: no seq#:0 ack#:2 payload_length:0 data_integrity:0 err_code:0
2019-04-17T12:22:51.871Z DEBUG 10076/ 0 <-  [02 33 00 00 00 00 00 00 00 04 00 06 00 03 28 01 07 00 04 2a 01 08 00 03 28 01 09 00 a6 2a 01 ]
               type:     VENDOR_SPECIFIC reliable:yes seq#:2 ack#:4 payload_length:1f data_integrity:1 header_checksum:1f err_code:0
2019-04-17T12:22:51.871Z DEBUG    10078 ->  []
               type:                 ACK reliable: no seq#:0 ack#:3 payload_length:0 data_integrity:0 err_code:0
2019-04-17T12:22:51.871Z DEBUG GATTC_EVT_DESC_DISC_RSP time:2019-04-17T12:22:51.871Z connHandle:0 gattStatus:0 gattStatusName:success errorHandle:0 count:4 descs:[[handle:6,uuid:[uuid:10243 type:1 typeString:bleUuidTypeBle]],[handle:7,uuid:[uuid:10756 type:1 typeString:bleUuidTypeBle]],[handle:8,uuid:[uuid:10243 type:1 typeString:bleUuidTypeBle]],[handle:9,uuid:[uuid:10918 type:1 typeString:bleUuidTypeBle]]]
2019-04-17T12:22:51.871Z DEBUG    10079 ->  [00 97 00 00 01 08 00 09 00 ]
               type:     VENDOR_SPECIFIC reliable:yes seq#:4 ack#:3 payload_length:9 data_integrity:1 header_checksum:86 err_code:0
2019-04-17T12:22:51.875Z DEBUG 10077/ 0 <-  []
               type:                 ACK reliable: no seq#:0 ack#:5 payload_length:0 data_integrity:0 err_code:0
2019-04-17T12:22:51.875Z DEBUG 10078/ 0 <-  [01 97 00 00 00 00 ]
               type:     VENDOR_SPECIFIC reliable:yes seq#:3 ack#:5 payload_length:6 data_integrity:1 header_checksum:a7 err_code:0
2019-04-17T12:22:51.875Z DEBUG    10080 ->  []
               type:                 ACK reliable: no seq#:0 ack#:4 payload_length:0 data_integrity:0 err_code:0
2019-04-17T12:22:52.071Z DEBUG GATTC_EVT_DESC_DISC_RSP time:2019-04-17T12:22:52.071Z connHandle:0 gattStatus:0 gattStatusName:success errorHandle:0 count:2 descs:[[handle:8,uuid:[uuid:10243 type:1 typeString:bleUuidTypeBle]],[handle:9,uuid:[uuid:10918 type:1 typeString:bleUuidTypeBle]]]
2019-04-17T12:22:52.071Z DEBUG 10079/ 0 <-  [02 33 00 00 00 00 00 00 00 02 00 08 00 03 28 01 09 00 a6 2a 01 ]
               type:     VENDOR_SPECIFIC reliable:yes seq#:4 ack#:5 payload_length:15 data_integrity:1 header_checksum:b5 err_code:0
2019-04-17T12:22:52.071Z DEBUG    10081 ->  []
               type:                 ACK reliable: no seq#:0 ack#:5 payload_length:0 data_integrity:0 err_code:0
2019-04-17T12:22:52.071Z DEBUG    10082 ->  [00 97 00 00 01 0a 00 09 00 ]
               type:     VENDOR_SPECIFIC reliable:yes seq#:5 ack#:5 payload_length:9 data_integrity:1 header_checksum:75 err_code:0
2019-04-17T12:22:52.075Z DEBUG 10080/ 0 <-  []
               type:                 ACK reliable: no seq#:0 ack#:6 payload_length:0 data_integrity:0 err_code:0
2019-04-17T12:22:52.075Z DEBUG 10081/ 0 <-  [01 97 00 00 00 00 ]
               type:     VENDOR_SPECIFIC reliable:yes seq#:5 ack#:6 payload_length:6 data_integrity:1 header_checksum:9d err_code:0
2019-04-17T12:22:52.075Z DEBUG    10083 ->  []
               type:                 ACK reliable: no seq#:0 ack#:6 payload_length:0 data_integrity:0 err_code:0
2019-04-17T12:22:52.370Z DEBUG 10082/ 0 <-  [02 33 00 00 00 01 01 0a 00 00 00 ]
               type:     VENDOR_SPECIFIC reliable:yes seq#:6 ack#:6 payload_length:b data_integrity:1 header_checksum:4c err_code:0
2019-04-17T12:22:52.370Z DEBUG    10084 ->  []
               type:                 ACK reliable: no seq#:0 ack#:7 payload_length:0 data_integrity:0 err_code:0
2019-04-17T12:22:52.370Z DEBUG GATTC_EVT_DESC_DISC_RSP time:2019-04-17T12:22:52.371Z connHandle:0 gattStatus:257 gattStatusName:atterrInvalidHandle errorHandle:10 count:0 descs:[]
2019-04-17T12:22:52.370Z DEBUG findCharacteristic: Found characteristic ID D4:D5:F6:7C:B1:8C.0.22.43
2019-04-17T12:22:52.370Z DEBUG Found unbonded buttonless characteristic: D4:D5:F6:7C:B1:8C.0.22.43
2019-04-17T12:22:52.371Z DEBUG    10085 ->  [00 9c 00 00 01 01 00 11 00 00 00 02 00 01 02 00 ]
               type:     VENDOR_SPECIFIC reliable:yes seq#:6 ack#:7 payload_length:10 data_integrity:1 header_checksum:f3 err_code:0
2019-04-17T12:22:52.373Z DEBUG 10083/ 0 <-  []
               type:                 ACK reliable: no seq#:0 ack#:7 payload_length:0 data_integrity:0 err_code:0
2019-04-17T12:22:52.373Z DEBUG 10084/ 0 <-  [01 9c 00 00 00 00 ]
               type:     VENDOR_SPECIFIC reliable:yes seq#:7 ack#:7 payload_length:6 data_integrity:1 header_checksum:93 err_code:0
2019-04-17T12:22:52.373Z DEBUG    10086 ->  []
               type:                 ACK reliable: no seq#:0 ack#:0 payload_length:0 data_integrity:0 err_code:0
2019-04-17T12:22:52.571Z DEBUG 10085/ 0 <-  [02 38 00 00 00 00 00 00 00 11 00 01 00 00 00 00 ]
               type:     VENDOR_SPECIFIC reliable:yes seq#:0 ack#:7 payload_length:10 data_integrity:1 header_checksum:f9 err_code:0
2019-04-17T12:22:52.571Z DEBUG    10087 ->  []
               type:                 ACK reliable: no seq#:0 ack#:1 payload_length:0 data_integrity:0 err_code:0
2019-04-17T12:22:52.571Z DEBUG GATTC_EVT_WRITE_RSP time:2019-04-17T12:22:52.571Z connHandle:0 gattStatus:0 gattStatusName:success errorHandle:0 handle:17 writeOp:1 offset:0 len:0
2019-04-17T12:22:52.571Z INFO Attribute value changed, handle: 0x11, value (0x): 02-00
2019-04-17T12:22:52.572Z DEBUG    10088 ->  [00 9c 00 00 01 01 00 10 00 00 00 01 00 01 01 ]
               type:     VENDOR_SPECIFIC reliable:yes seq#:7 ack#:1 payload_length:f data_integrity:1 header_checksum:33 err_code:0
2019-04-17T12:22:52.574Z DEBUG 10086/ 0 <-  []
               type:                 ACK reliable: no seq#:0 ack#:0 payload_length:0 data_integrity:0 err_code:0
2019-04-17T12:22:52.574Z DEBUG 10087/ 0 <-  [01 9c 00 00 00 00 ]
               type:     VENDOR_SPECIFIC reliable:yes seq#:1 ack#:0 payload_length:6 data_integrity:1 header_checksum:d1 err_code:0
2019-04-17T12:22:52.574Z DEBUG    10089 ->  []
               type:                 ACK reliable: no seq#:0 ack#:2 payload_length:0 data_integrity:0 err_code:0
2019-04-17T12:22:52.770Z DEBUG 10088/ 0 <-  [02 38 00 00 00 00 00 00 00 10 00 01 00 00 00 00 ]
               type:     VENDOR_SPECIFIC reliable:yes seq#:2 ack#:0 payload_length:10 data_integrity:1 header_checksum:2f err_code:0
2019-04-17T12:22:52.770Z DEBUG    10090 ->  []
               type:                 ACK reliable: no seq#:0 ack#:3 payload_length:0 data_integrity:0 err_code:0
2019-04-17T12:22:52.770Z DEBUG GATTC_EVT_WRITE_RSP time:2019-04-17T12:22:52.771Z connHandle:0 gattStatus:0 gattStatusName:success errorHandle:0 handle:16 writeOp:1 offset:0 len:0
2019-04-17T12:22:52.770Z INFO Attribute value changed, handle: 0x10, value (0x): 01
2019-04-17T12:22:52.772Z DEBUG 10089/ 0 <-  [02 39 00 00 00 00 00 00 00 10 00 02 03 00 20 01 01 ]
               type:     VENDOR_SPECIFIC reliable:yes seq#:3 ack#:0 payload_length:11 data_integrity:1 header_checksum:1e err_code:0
2019-04-17T12:22:52.772Z DEBUG    10091 ->  []
               type:                 ACK reliable: no seq#:0 ack#:4 payload_length:0 data_integrity:0 err_code:0
2019-04-17T12:22:52.772Z DEBUG GATTC_EVT_HVX time:2019-04-17T12:22:52.773Z connHandle:0 gattStatus:0 gattStatusName:success errorHandle:0 handle:16 type:2 len:3
2019-04-17T12:22:52.772Z INFO Attribute value changed, handle: 0x10, value (0x): 20-01-01
2019-04-17T12:22:52.773Z DEBUG    10092 ->  [00 9d 00 00 10 00 ]
               type:     VENDOR_SPECIFIC reliable:yes seq#:0 ack#:4 payload_length:6 data_integrity:1 header_checksum:b2 err_code:0
2019-04-17T12:22:52.773Z DEBUG Waiting for target device to disconnect.
2019-04-17T12:22:52.776Z DEBUG 10090/ 0 <-  []
               type:                 ACK reliable: no seq#:0 ack#:1 payload_length:0 data_integrity:0 err_code:0
2019-04-17T12:22:52.776Z DEBUG 10091/ 0 <-  [01 9d 00 00 00 00 ]
               type:     VENDOR_SPECIFIC reliable:yes seq#:4 ack#:1 payload_length:6 data_integrity:1 header_checksum:c6 err_code:0
2019-04-17T12:22:52.776Z DEBUG    10093 ->  []
               type:                 ACK reliable: no seq#:0 ack#:5 payload_length:0 data_integrity:0 err_code:0
2019-04-17T12:22:56.970Z DEBUG 10092/ 0 <-  [02 11 00 00 00 08 ]
               type:     VENDOR_SPECIFIC reliable:yes seq#:5 ack#:1 payload_length:6 data_integrity:1 header_checksum:c5 err_code:0
2019-04-17T12:22:56.970Z DEBUG    10094 ->  []
               type:                 ACK reliable: no seq#:0 ack#:6 payload_length:0 data_integrity:0 err_code:0
2019-04-17T12:22:56.970Z DEBUG GAP_EVT_DISCONNECTED time:2019-04-17T12:22:56.970Z connHandle:0 reason:8 reasonName:connectionTimeout
2019-04-17T12:22:56.970Z DEBUG Received disconnection event for target device.
2019-04-17T12:22:56.970Z DEBUG New address for DFU target: D4:D5:F6:7C:B1:8D
2019-04-17T12:22:56.970Z DEBUG Connecting to address: D4:D5:F6:7C:B1:8D, type: BLE_GAP_ADDR_TYPE_RANDOM_STATIC.
2019-04-17T12:22:56.973Z DEBUG    10095 ->  [00 8c 01 02 8d b1 7c f6 d5 d4 01 01 a0 00 50 00 14 00 01 06 00 06 00 00 00 90 01 ]
               type:     VENDOR_SPECIFIC reliable:yes seq#:1 ack#:6 payload_length:1b data_integrity:1 header_checksum:50 err_code:0
2019-04-17T12:22:56.977Z DEBUG 10093/ 0 <-  []
               type:                 ACK reliable: no seq#:0 ack#:2 payload_length:0 data_integrity:0 err_code:0
2019-04-17T12:22:56.977Z DEBUG 10094/ 0 <-  [01 8c 00 00 00 00 ]
               type:     VENDOR_SPECIFIC reliable:yes seq#:6 ack#:2 payload_length:6 data_integrity:1 header_checksum:bc err_code:0
2019-04-17T12:22:56.977Z DEBUG    10096 ->  []
               type:                 ACK reliable: no seq#:0 ack#:7 payload_length:0 data_integrity:0 err_code:0
2019-04-17T12:22:57.000Z DEBUG GAP_EVT_CONNECTED time:2019-04-17T12:22:56.999Z connHandle:0 peerAddr:[address:D4:D5:F6:7C:B1:8D type:randomStatic addrIdPeer:0] role:central connParams:[minConnInterval:7_5 maxConnInterval:7_5 slaveLatency:0 connSupTimeout:4000]
2019-04-17T12:22:57.005Z DEBUG 10095/ 0 <-  [02 10 00 00 00 02 8d b1 7c f6 d5 d4 02 06 00 06 00 00 00 90 01 ]
               type:     VENDOR_SPECIFIC reliable:yes seq#:7 ack#:2 payload_length:15 data_integrity:1 header_checksum:ca err_code:0
2019-04-17T12:22:57.005Z DEBUG    10097 ->  []
               type:                 ACK reliable: no seq#:0 ack#:0 payload_length:0 data_integrity:0 err_code:0
2019-04-17T12:22:57.005Z DEBUG    10098 ->  [00 94 00 00 01 00 00 ]
               type:     VENDOR_SPECIFIC reliable:yes seq#:2 ack#:0 payload_length:7 data_integrity:1 header_checksum:c0 err_code:0
2019-04-17T12:22:57.009Z DEBUG 10096/ 0 <-  []
               type:                 ACK reliable: no seq#:0 ack#:3 payload_length:0 data_integrity:0 err_code:0
2019-04-17T12:22:57.009Z DEBUG 10097/ 0 <-  [01 94 00 00 00 00 ]
               type:     VENDOR_SPECIFIC reliable:yes seq#:0 ack#:3 payload_length:6 data_integrity:1 header_checksum:ba err_code:0
2019-04-17T12:22:57.009Z DEBUG    10099 ->  []
               type:                 ACK reliable: no seq#:0 ack#:1 payload_length:0 data_integrity:0 err_code:0
2019-04-17T12:22:57.039Z DEBUG 10098/ 0 <-  [02 11 00 00 00 3e ]
               type:     VENDOR_SPECIFIC reliable:yes seq#:1 ack#:3 payload_length:6 data_integrity:1 header_checksum:b9 err_code:0
2019-04-17T12:22:57.039Z DEBUG    10100 ->  []
               type:                 ACK reliable: no seq#:0 ack#:2 payload_length:0 data_integrity:0 err_code:0
2019-04-17T12:22:57.039Z DEBUG GAP_EVT_DISCONNECTED time:2019-04-17T12:22:57.039Z connHandle:0 reason:62 reasonName:connFailedToBeEstablished
2019-04-17T12:22:57.039Z DEBUG Did not find service changed. Error: Error: Device disconnected
2019-04-17T12:22:57.040Z DEBUG Destroying DFU transport.
2019-04-17T12:22:57.040Z ERROR DFU failed with error: Cannot read property 'instanceId' of undefined.

After such a failure message, I can try to the DFU again, and sometimes it will succeed.