After closing com connection my app's GUI freezes.

[code_err]

I have a function which receive data through com port via qextserialport library. When function receives wrong data it closes port but then gui freezes and seem not to respond to my actions (but when move main window performed gui actions start to be visible but still gui is frozen).
When i make a new connection through com port gui stop to be frozen and respond normally.

Do you know what i mean? Don't know what could be the cause of this behavior.

[ChrisW67]

Do you know what i mean?

Maybe. The cause of this behaviour is in your code. Perhaps you could produce a small, compilable example that demonstrates this problem.