[SeggerBackend] JLinkARM.dll reported "-1", "An unknown error.".

[Katelyn Dimmell]

Hello,

I am trying to program an nRF9160 chip using pynrfjprog v10.15.2 and JLinkARM.dll version: 6.88 with a Segger Flasher Compact. This flasher supportd the nRF9160. I downgraded the J-Link version from v7.60 as per the recommendation on a earlier ticket to be compatible with nRF Connect v3.7 (https://devzone.nordicsemi.com/f/nordic-q-a/84153/unsupported-device-the-detected-device-could-not-be-recognized-as-neither-jlink-device-nor-nordic-usb-device). 

My problem is nrfjprog cannot reliably find the debugger. Sometimes it works miraculously even though nothing has changed but most of the time it cannot find it. When I try to connect to the debugger in  nRF Connect v3.7 I get this error:

Could not fetch memory size of target devkit: Error: Error occured when get library info. Errorcode: CouldNotOpenDevice (0x4) Lowlevel error: JLINKARM_DLL_ERROR (ffffff9a)

In nRF Connect v3.9 it says the debugger is not a recognized device. 

I get this error using pynrfjprog:

[DebugProbe] Failed to connect to debug probe

[SeggerBackend] JLinkARM.dll reported "-1", "An unknown error.".

The debugger can be seen in device manager:

and in nRF Connect:

For whatever reason, the nrfjprog cannot find the debugger on the backend. Any help would be very much appreciated.

[Marte Myrvold]

Hi,

We recently released v3.10 of nRF Connect. Can you try updating to this version and see if the issue still persists? There should be a newer version of J-Link bundled with the update as well, but if J-Link is not updated automatically please download and install v7.58b from here: https://www.segger.com/downloads/jlink. You can check the version of J-Link with the command 'nrfjprog -v'. Remember to also update the Programmer app to v2.3.1.

Let me know if you still get this issue after updating and I will forward it to our developers. If that is the case please share the logs from the Programmer. In the latest version there is an added feature to get additional logging. You can enable it by going to the About tab in the Programmer and selecting Verbose logging. To get logs from the beginning please select Restart with verbose logging. After the app restarts select Open log file at the bottom of the terminal to get the log file and upload it here with Insert -> Image/Video/File. Please be aware that verbose logging will lead to rather large log files, so you should not have the option enabled unless you need to send the logs for support, as they can fill up the space on your computer quickly. 

Best regards,

Marte