Hello,
Just want to ask how to solve this issue? I am using J-Link with updated version.
I also did 'erase all' before updating the modem and flashing. I succeeded on initial few samples but then suddenly
this error happened. Now I even cannot re-flash those units that were good earlier.
I'm using external J-Link.
What I did is I use RTT viewer to check log report.
Then open nRF programmer to erase all -> update modem -> flash hex, but I'm just until erase all...
Could you share the full log from the programmer app: 
after running the modem update ?
Also please shut all other serial terminal e.g. like RTT Viewer, so that the Jlink is only used when using the programmer app.
Do you have any idea what may have happened between the flashing the ones that worked vs. the ones that does not work?
The RTT Viewer was required by our customer to verify the public and private key.
The steps I did were below.
1) Open RTT Viewer and verifiy the device is connected.
2) Open nRF Programmer, at first i did not perform erase all command, just straight to update modem
and flash hex. I did it for the 15 samples or so and it worked. Then after some time the error came out.
***by the way, before this issue I flashed all 20 units with no problem. Then the customer required to view the log file for public and private key that is why I needed the RTT Viewer and reflash the units again*** Is it possible that the nRF9160 was corrupted or some sort?
Here is the log file data.
2020-07-30T07:30:35.154Z INFO Application data folder: C:\Users\Engineer\AppData\Roaming\nrfconnect\pc-nrfconnect-programmer
2020-07-30T07:30:35.452Z DEBUG App pc-nrfconnect-programmer v1.4.3 official
2020-07-30T07:30:35.453Z DEBUG App path: C:\Users\Engineer\.nrfconnect-apps\node_modules\pc-nrfconnect-programmer
2020-07-30T07:30:35.453Z DEBUG nRFConnect 3.4.1 is supported by the app (^3.3.0)
2020-07-30T07:30:35.453Z DEBUG nRFConnect path: C:\Users\Engineer\AppData\Local\Programs\nrfconnect\resources\app.asar
2020-07-30T07:30:35.453Z DEBUG HomeDir: C:\Users\Engineer
2020-07-30T07:30:35.453Z DEBUG TmpDir: C:\Users\Engineer\AppData\Local\Temp
2020-07-30T07:30:35.491Z INFO Using nrfjprog library 10.9.0, pc-nrfjprog-js 1.7.3
2020-07-30T08:48:10.473Z INFO Using nrfjprog to communicate with target
2020-07-30T08:48:11.072Z INFO Using J-Link Software version 6.82
2020-07-30T08:48:11.958Z INFO Segger serial: 269402668
2020-07-30T08:48:11.958Z INFO Segger speed: 2000 kHz
2020-07-30T08:48:11.958Z INFO Segger version: J-Link V9 compiled Dec 13 2019 11:14:50
2020-07-30T08:48:11.963Z INFO Core probed: 269402668.
2020-07-30T08:48:11.963Z INFO Core RAM: 256KiB.
2020-07-30T08:48:11.963Z INFO Core ROM: 1024KiB in pages of 4KiB.
2020-07-30T08:48:12.242Z INFO Model: NRF9160_xxAA_REV2.
2020-07-30T08:48:12.721Z INFO Core0: Reading device non-volatile memory. This may take a few seconds.
2020-07-30T08:48:12.893Z INFO Core0: UICR has been read. Click read button to read full non-volatile memory.
2020-07-30T08:56:15.121Z INFO Modem DFU starts to write...
2020-07-30T08:56:15.121Z INFO Writing D:\DESIGN PROJECTS 2019\MEO LIFE\FW\nRF\mfw_nrf9160_1.2.0.zip to device 269402668
2020-07-30T08:56:16.960Z INFO Checking for newer bootloader.
2020-07-30T08:56:16.963Z INFO Newer bootloader discovered, re-initializing.
2020-07-30T08:56:17.293Z INFO Programming file 0 of 2 files.
2020-07-30T08:56:17.315Z INFO Programming 1 of 1 segments.
2020-07-30T08:56:17.479Z INFO Programming finished.
2020-07-30T08:56:17.483Z INFO Programming file 1 of 2 files.
2020-07-30T08:56:18.686Z INFO Programming 1 of 32 segments.
2020-07-30T08:56:18.794Z ERROR Modem DFU failed with error: Error: Error occured when program. Errorcode: CouldNotCallFunction (0x9)
Lowlevel error: JLINKARM_DLL_ERROR (ffffff9a)
2020-07-30T08:56:24.359Z INFO Modem DFU starts to write...
2020-07-30T08:56:24.360Z INFO Writing D:\DESIGN PROJECTS 2019\MEO LIFE\FW\nRF\mfw_nrf9160_1.2.0.zip to device 269402668
2020-07-30T08:56:25.959Z INFO Checking for newer bootloader.
2020-07-30T08:56:25.962Z INFO Newer bootloader discovered, re-initializing.
2020-07-30T08:56:26.294Z INFO Programming file 0 of 2 files.
2020-07-30T08:56:26.330Z INFO Programming 1 of 1 segments.
2020-07-30T08:56:26.477Z INFO Programming finished.
2020-07-30T08:56:26.479Z INFO Programming file 1 of 2 files.
2020-07-30T08:56:27.700Z INFO Programming 1 of 32 segments.
2020-07-30T08:56:28.133Z ERROR Modem DFU failed with error: Error: Error occured when program. Errorcode: CouldNotCallFunction (0x9)
Lowlevel error: Unknown value (ffffffa3)
