So, as I move my items inside my inventory, they're looking normal. But when I am trying to use them, for example build a stone, it is disappearing miliseconds after using and block that was in this slot before is being placed. I can move things in my inv only when using furnance, chest and other things like this, even backpack work. My friends inv is working normally. In singleplayer and other servers everything is ok. It is actually super annoying. Any idea?

And sorry if I am hard to understand, you know, I am Polish and not using English everyday.

Edited May 8, 20187 yr by I Midoriya I
mistake

17 hours ago, I Midoriya I said:

In singleplayer and other servers everything is ok

 

17 hours ago, I Midoriya I said:

My friends inv is working normally.

Reinstall Minecraft & Forge.

I had a bug like this in 1.5 or something. I fixed by deleting my player data file on the server. You could try this, It is probably a bad solution, and you will loose everything in your inventory (and all your other player data)