Add frame and most of the other right click options in the Animation frames and Animations windows seem like they can't be selected, but clicking on them works normally.
I can't reproduce this, they appear fine here on Windows 8. Can you provide any more information about your system and whether this occurs on any other computers you have access to?
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After restarting a couple of times the bug seems to be gone.
Can't reproduce anymore, it happened right after upgrading from 108.2 to 109 and creating a new project. I checked an old project and it was the same there too.