[keine idee]

When trying to import audio, drag from Finder or drag from Workspace, it doesn't work for any files in our sound library that end with .aiff - since we updated to 2019.12 from 2018something.
It works with all other file formats (.aif, .wav, .mp3, etc.).
In a soundbase workspace I tried to disable those files which only worked when I chose 'format is not quicktime', which confused me because I expected they would be aiff.

We have this problem with all three Apple Computers that we updated (Mac Pro Late 2013, MacBook Pro 2015 and an iMac Pro from 2017).
All three are on High Sierra 10.13.6.
It doesn't matter if the files are locally present or on a drive.

On the iMac I would also get this error message: Assertion in "/Volumes/Development/238958/ProTools/NewFileLibs/FF/Audio/FF_AudioFile.cpp", line 1339.

With the MacBook I installed 2019.10 to check where the problem is and I could listen to the files and import them without any problems.
So I suppose it must be either the ProTools version itself oder the combination with High Sierra?

I couldn't find anything on this topic.. does anyone else have such a problem? Or has something like it happened to you before and you have an idea for a solution?