Whenever I try to export some projects Media encoder can't open them. I tried reinstalling both Adobe After Effects and Adobe Media Encoder but I can't get it to work.
What version of After Effects and Media Encoder are you working with? This is a known issue with After Effects 17.0.6 and Media Encoder 14.1. Here is some more information on this issue:
Thanks for reaching out. Our product team is aware of this issue and they are researching on it. I researched and found some information.
Check out this article: Unable to render/export After Effects comps through Media Encoder
Let us know if you have any questions.