No JLink Device Found. Flash download failed - Target DLL has been cancelled

[daniel77]

I just setup Keill uVision V5.21 with nRF52 DK. I was able to flash the ble_app_uart example onto the board. When I realized that I missed out the softdevice, I just drag and drop the s132_nrf52_3.0.0_softdevice.hex into the DK USB drive. The board runs well with nrf Connect detected the DK and able to connect to the DK. But, when I return to Keil to work on RedBearLab BLE Nano with this "No JLink Device found". Later, I switch back to nRF52 DK with same/another example and download a new file, the error said

No JLink Device Found. 

Error: Flash download failed - Target DLL has been cancelled

The board no longer able to see the DK USB drive. I pressed the IF BOOTLOADER/RESET button and do a power cycle to get the drive up as BootLoader drive. Dragged and dropped the nRF5x-OB-JLink-IF onto the drive. But, the same error appears preventing me from flashing new app.

[daniel77]

Alright, I found the answer from another post. There were many posts and many answers related to this that were confusing. Just reinstall the nRF5x-Command-Line-Tools and then check the box to replace the JLinkARM.dll in C:\Keil_v5\ARM\Segger. My advice is for Nordic to put this onto the Keil installation tutorial than letting user search through the answers one by one.

[Petter Myhre]

Thanks for adding an answer, and for the feedback.