I have been using AE for a long time and now bumped in to a very strange problem:
I cannot drag a precomp from the project panel into my timeline, it simply won't appear there. If I drag another comp from the project panel to this timeline, it works just fine. And no, this is not the same comp that I have open that I'm trying to drag in. The comp I'm trying to add contains two layers and a track matte.
Does anyone have any ideas/suggestions on how to troubleshoot this?
Okay problem solved!
I found out that the comp I was trying to drag in actually had the comp I was in as a layer :S
Thanks for reporting back with the resolution.