I'm currently working with two different projects in Premiere Pro and After Effects and experiencing crashes when using the "Replace with After Effects composition" function in Premiere. One of the two projects worked just fine but when I switched to the other one, Premiere would just crash without even opening After Effects.
This is weird because I had no problems working with the first project on both apps. I've tried resetting my preferences, media cache files, setting the audio input to none and creating another project importing the sequence (which I couldn't do because Premiere also crashes importing), but nothing seems to work and now both my projects display "Media Pending" when I open them.
Sorry to hear you're experiencing this problem. Please let us know if you're using any third-party plugins in your project, and share your current Premiere Pro and After Effects versions (Help > About Premiere Pro/After Effects). If you see the crash reporter dialog box, please click on the View Report button and share it with us using any cloud file-sharing service. That can help us better understand the problem.