[Kai Mariah] “I tried reinstalling FCP and Compressor. That didn’t work.”
They must be uninstalled but you do a reinstall and Compressor parts are all over the place, there is an app by Digital Rebellion that is a must for removing FCS apps.
This problem can be cause by a bad clip or filter, it is sometimes a pain to find the cause.
Duplicate the timeline and remove on the filters (remove attributes – Filters) and see if that renders or exports out, using the simple Self contained movie with Current settings. If that works you have a filter issue. If it doesn’t list what hardware and drives you have installed.