https://devzone.nordicsemi.com/f/nordic-q-a/61240/default-interrupt-handler-called-on-usbd-power-eventHi I am developing a bootloader for nRF52840 using SDK 15.2.0 and s140_nrf52_6.1.0_softdevice, that should support both USBD and BLE transports. The first transport layer initiated inside &#39;nrf_dfu_transports_init&#39; is the USBD (&#39;usb_dfu_transport_initen-USTelligent Community 13Tue, 12 May 2020 07:54:13 GMThttps://devzone.nordicsemi.com/thread/249359?ContentTypeID=1Tue, 12 May 2020 07:54:13 GMT137ad170-7792-4731-bb38-c0d22fbe4515:adfa35f1-7f95-4ab7-8b22-bbd57ff32e13Simonr<p>Hi Yaron</p> <p>Is your APP_USBD_CONFIG_POWER_EVENTS_PROCESS enabled in your project?</p> <p>We saw a similar problem some time ago, where the workaround ended up being to use the gcc compiler instead of Keil, which showed this issue. Please try the attached project in the armgcc folder. It should use default keys placed in <strong>SDK15.2\examples\dfu&nbsp;</strong></p> <p><a href="https://devzone.nordicsemi.com/cfs-file/__key/support-attachments/beef5d1b77644c448dabff31668f3a47-27b3ccf72a754177840461bea0f6f49f/pca10056_5F00_ble_5F00_and_5F00_uart.zip">devzone.nordicsemi.com/.../pca10056_5F00_ble_5F00_and_5F00_uart.zip</a></p> <p>Best regards,</p> <p>Simon</p><div style="clear:both;"></div>