[Brian Cramer]

For anyone that finds this thread and is looking for an answer as I was…

I ended up using handbrake (https://handbrake.fr/) it’s an open source video transcoder and it’s free.

I convert any mkv and avi to mp4 and they always import into After Effects without issue. A couple times I had damaged mp4s(float issues) and I converted from mp4 to mp4 in handbrake that worked too. This does take a good 10+ minutes to convert an hour long video, so if there is any quicker way I’d love to hear!