When I open the mod in any world, including servers the entire screen starts vibrating quickly. It's extremely annoying and impossible to play with.
EDIT: It's more so the player shaking than the entire world. After realizing this, I did some research and realized this is a compatibility problem with the More Player Models mod. It's a result of scaling the player model. I fixed it, but it's too bad.

I can't fix that. It's a general mod incompatibility, but I'm glad you found out a solution.