Honestly, I'd revert to using AE CC 2017.
Ever since Adobe went to Creative Cloud, initial releases of new AE versions are riddled with bugs. Macs seem to be particularly vulnerable this time.
I always recommend holding off on new versions until the first major bug fix. Preferably the second bug fix.
Thanks for the reply. Disappointing that this is the solution, but I think you are right.
Uh i had the same problem and what i saw on YouTube to fix this problems~ go to run type in %appdata% enter~ go to adobe and there should be too after effects folder rename the second folder to "after effects old" and open after effects should work~
And also do not use create composition with footage thats a buggy one just use new composition