Actually I can't english well, so I copy this Question from the same problem on me.
Hello, I've been using SeeMusic for a while, and this problem has happened on and off. I'm using Mac. After exporting, the saber in the final video sometimes abruptly "restarts," causing it to go from one position to a completely different one the very next frame, instead of gradually and smoothly moving as it usually does. Is there a way to fix this? This happens with any of the three saber presets included with the software.
Hmm... that's very unusual, and shouldn't be happening. The VideoPlayer feature of Unity, which is used for video playback of the saber, is notoriously difficult to work with, and can occasionally exhibit unpredictable bugs like this. This isn't something I'm able to replicate on the Macs I have available, although I will keep trying.
Can you let me know the specifications of your Mac?
You can send a screenshot of the "About This Mac" window if thats easy.