Could not fetch memory size of target devkit: Error: Error occured when get library info. Errorcode: CouldNotOpenDevice (0x4) Lowlevel error: Unknown value (ffffff5e)

[christian11]

I have seen this question asked a few times--but every thread seems to have no concrete answer.

I have uninstalled and reinstalled all JLINK drivers.

But still get the errors.

I have nrf52840 dk and am using windows 10

[Albrecht Markus Schellenberger]

Hello Christian,

christian11 said:

When connected, only one of the 3 shows up:

Yes, that would be correct.

Could you navigate to your JLink folder and open the "JLinkConfig.exe"?

For a working device (which is powered-on), you should get a window like this:

Alternatively, you could use the terminal running “JLink.exe”. It should look like this:

Regards,

Markus