I would like to compile using ArduinoIDE2.0.0, but I am having the same trouble. ArduinoIDE1.8.19 does not cause any problems, so I will use this for the time being.
I am using Arduino IDE 2.0, have selected the Seeed nRF52 mbed-enable Boards and am using the Blink program, the compilation is passing and I am not having the problems you are having, is there any more information to help me identify the problem?
IF I may ,
It’s a well reported problem with the compile and upload, YOU must select the BOARD and PORT each time. Watch the status bar at the bottom of the screen you will see when it’s connected. I have a video link on here demonstrating it. and the proper work flow.
In my environment, @msfujino 's first problem has already been solved.
The second FQBN error only happens when the board selection is “Seeed XIAO BLE Sense - nRF52840” (mbed).
Would you reproduce this situation in @Citric 's environment?
Thank you, we have reviewed the issue and reported it to R&D, we will update here as soon as we have any new information. We apologise for any inconvenience caused.