I crashed while right clicking on the side of a stone slab with a anvil.

Thank you for your report.
However, your ticket has been resolved as incomplete.

We are unable to diagnose your issue due to the lack of proper debug information. Please review the guidelines before reporting issues.
In case of a game crash, please also attach the crash log from [minecraft/crash-reports/crash-<DATE>-client.txt|http://hopper.minecraft.net/help/finding-minecraft-data-folder].

Reminder: For technical support please use the Mojang Support Center.

Sorry, thought it automatically uploaded it when i click 'report crash to mojang'.

Is the server modded and/or was the anvil spawned in?

No, it has plugins, i had a regular anvil and i placed it on a slab, i will send screenshot of the area.

It looks like one of the plugins is causing the anvil to have a wrong damage value.

its a anvil i promise, just weird texture. i'm not using a texture pack.

Hmm so not a mojang/minecraft cause, what plugin if you can tell?

Definitely caused by plugins then. Contact the server owner. This ticket is invalid since it contains a modified server environment.