I shifted several tens of clips with effects and transitions by selecting them all with shift drag, only to find them completely garbled: especially pan and zoom effects had to be redone completely. However, after manually restoring my project, I am stuck with two vertical lines through the bottom edge of the track. I can select them, and they show as orphan dissolve transitions, not attached to any clip. I can move them around, but there does not seem to be a way to delete them?