Thank you for your answer! Today, I found the solution:
My RTX 2080ti has 2 Display-Ports and one HDMI-Port.
Unfortunately CT opened a dialogue-box on the HDMI-Output, but there was no screen connected.
That's why I had to press ESC to continue working. Today I pressed ESC in an other application to
close the dialogue-box and then I thought, that maybe the dialogue-box in CT could be outside the screens...
Connecting the HDMI-port brought the solution - bam, there is the dialoguebox for importing audio
Well, at least I have all drivers of my system re-installed
Kind regards from Cologne, Richard
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