Game crashes when joining server

Greetings everybody,
we got our own server set up, no mods used at all.

Today i wanted to create a stack of cloth via chat command.
I dont exactly remember what i typed, but it was something like "/give <my name> 36 64".
After like 2 seconds the game crashed down. I tried to rejoin a few times, however attached the first crash report.

Now i get ArrayIndexOutOfBoundsException: 64
Seems like the "item.tile.cloth.white" i added is the problem.

The chat command worked and it did not display error message. So why does it keep crashing when i entered a possible command?