@jsulm there was in fact a problem with window3d() that MinGW didnt complain about! Thanks! @JonB no I had commented out only up to the second screenshot, so that's why this was the problem.
And about the second issue, to be honest I adapted the constructor from an older version of the application and it also had &argc. At one point I also noticed it and now I tried out both and both work.
Thank you for you help.
Probably the thing is, QSerialPort has a problem to work in a new thread.
I can handle the other QObject in a new thread very well, and the exception only happens when the Object contains QSerialPort.
Also, in my last post, I actually never user QList, although Qt tells me something wrong with QList.
I have given up on working serialThread. QSerialPort does work good in the main thread.
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