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

[christian11]

 nRF Command Line Tools is installed on the C: drive, in the same location as the J-Link.

nRF connect is installed in the C: drive in a different location.

[Albrecht Markus Schellenberger]

Hello Christian,

christian11 said:

nRF Command Line Tools is installed on the C: drive, in the same location as the J-Link.

That is good.

christian11 said:

nRF connect is installed in the C: drive in a different location.

Is it the default location (which I might recommend to use at the moment)?

In your Device Manager, is there a JLink UART Port visible (similar to as shown in the picture below, which is from the nRF9160 that has 3 JLink UART ports)?

Regards,

Markus

[christian11]

Markus,

When connected, only one of the 3 shows up:

[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