If you compile it or if you run it? If it’s crashing when compiling the blueprint, it looks like a hot reload problem. Try to close the editor, build it in VS, then start the editor and try again. Always do it this way or use live-coding. If it’s not working, try it with a new blueprint. Hot reload is deprecated and can cause much problems.
If this is not the problem, then sorry, I don’t know. I just followed the chain from FMovieSceneChannel and searched for a function that seems to evaluate a curve. It’s worth a try, but I have no deeper understanding of the sequencer code.