With the QuickScribe window open, at the moment when the page is about to change for the successive one, this appears

and nothing more happens, DP just freezes.
I have waited for 15 minutes and nothing changed, not even the scrolling bar scrolls……
In the dock there is "The application is not responding" instead of "Quit" and I have to force quit.
I have restarted DP various times and then the Mac too, and the problem still persists.
I did not found nothing about this in the user manual.
I don't understand what means "Transcribing MIDI", what MIDI there is to transcribe?
I think that it could be a problem with the VI RealGuitar, but I am not sure.
Thanks for any help
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Edit:
1) The culprit is not RealGuitar, as the problem occurs even removing the VI.
2) In DP 7.24 all works perfectly.