Hey Adobe community! Hope someone can lend me a hand on my current project. I started putting together a mosh up of a tv series I enjoyed and after downloading all the footage I realized the videos were all mkv files with variable frame rates. Cool no worries, I'll just bust out my handy Handbrake tool and convert them to constant frame rate and mp4 files. Done. Footage looks and sounds good in both Quicktime and VLC. No out of sync issues. Imported footage into premiere last night and started editing. Everything was going smooth I was making a lot of progress and edited for almost 12 hours straight, still no audio issues. Went to bed and woke up the next morning ready to edit. I opened the project and everything I had edited so far was still in sync, but when I went to select new clips from the source, the audio was now out of sync and running ahead by a significant margin (several minutes). I double checked the files and they're still a constant frame rate so vfr is not the issue. I tried changing changing the files from mp4 to mov, but then premiere would crash whenever I tried importing those clips. I tried reimporting the footage and that didn't work; I tried starting a new project and importing, but that didn't help either. At this point the footage/audio still works in Quicktime/VLC, its only in premiere pro that it becomes out of sync. I've been searching the internet for about 3 hours now looking for a solution, but everything is related to it being a vfr issue, which is not my problem as the footage is all constant frame rate at 60 frames per second. 1920x1080. Running the latest version of Premiere Pro and I'm working on a 2016 Macbook Pro running Mojave. I should mention not all the clips are out of sync, out of about 14 video files only three of them are not working. Its strange because I converted them all with the same process so I would think they would either all work or none of them would work. Most of the files are about 24 minutes in length while two of them are around an hour and a half. Out of the three videos not working, one of them is an hour and 20 minutes while the other two are both 24 minutes. If needed I can try to provide more information on what I'm working with.