Sequence is only 4 minutes, but it says it's an hour long and there are no slugs at the end

I am working on a piece that is 4 min long for about a week and everything has been fine. I was editing today and hit shift-z to see the whole timeline and it magically changed into an hour long sequence. There is no filler to delete or other tracks that is filling out the rest of the time. I quit out and when back in several times and it still is the same. Any ideas?

Also I noticed that my video goes black and I have to restart to see it.

Need a LOT more information to diagnose what might be going on here. In particular, format, frame rate and codec.

Ok, I am working with Red files and 7d ftg that I converted to pro res 422 (HQ). I am using the proxy media. Project is running at 23.98. The red footage is both 4k and 2k and the 7d is 1080 and all running at 23.98.

Maybe you can create a new project, then copy/paste the content of the problematic project into the new one to see if this solves the issue.

I've seen tiny gap clips get orphaned off and cause this. But also try File > Delete Renders.