Bug/Issue Help! Transferred files and game is pretty much broken

I transferred a character from unstable to stable, both versions are incredibly slow and screwed up.
Every 10 - 25 seconds everything freezes for up to 10 seconds. And after travelling around 50 blocks I hit an invisible wall, my gaming pc is very good but after this transfer everything seems to be screwed up. All I did was copy my files from unstable for universe and player and replaced them in the normal, but now both stable and unstable are not playing properly.