Access violation while alt-tabbing from an actively updated plot widget

[dumdidum]

Hurr, yeah. I get your hint now that I read the code and documents for a while: this is a threading problem. I replaced the direct function call from another thread with a signal-slot connection, which makes sure that the setData() call is handled in the appropriate thread.

Many thanks for your guidance!

Although QObject is reentrant, the GUI classes, notably QWidget and all its subclasses, are not reentrant. They can only be used from the main thread.