I can't move items in the inventory quickly and dont move

What i expected to happen was...
Is that i could still play normally

What actually happened was...:
I was messing with the game files and accidentally deleted some and now when i move inventory items, i cant do it and also in the servers and worlds list there is that arrow that shows when you move your mouse over it but i can't remove it
Steps to Reproduce:
1. Show a video showing all the files so that i can know what are the ones that i am missing
2. Then when i finish doing that i need to know what type of file is each one (not creating one, just copying and pasting another file with the same dot at the end that i already have)
3. Then i can play it normally and without any problems