In my Cinema4d / After Effect workflow, I encounter this:
When a .mov from C4d is imported, and the Comp using it is the active Comp,
when I overwrite it (rerender it in Cinema4D), and - accidentally - switch to Ae while the render has not yet finished, Ae is complaining, and never let me use that .mov, or the rerender again. Ae seems to 'ban' the filename: when I rename it in Finder, it imports fine.
I think Ae should be more tolerant, and just mark the file as offline, to become online later.
I am on MacOS 12.6 / Ae 23.1.0.83 / C4d 2023.1.2