For some strange reason, lip files randomly stop working. Frustratingly, the issue is extremely hard to reproduce. Sometimes a line of dialogue is synced correctly, and sometimes the characters lips do not move at all. The issue appears to be random - however, it seems to have only started happening since the latest update.
Here's a video of some of the issues (mouth tearing, choppy animation, gaping etc.): https://www.dropbox.com/s/jjcd4ui0vyeefso/Lip%20Issue.avi?dl=0