does this happen to you? motion tween isseue

this happened to me twice and im furious

i made a motion tween for an animation that i had to do over because of the same issue, doing so will freeze the program. It will not unfreeze until you close it, which the softwere forgets the entire animation completely. It just vanishes with no trace. please someone help me find these lost animations and fix this dumb issue, my sanity is on the line