TSR works fine on singleplayer. But when trying to place a solid camo block on my server, it crashed.
On server reload, the camo block showed up fine. When trying to place a camo block, the server crashed again.
On server reload, both blocks showed up fine. I then grabbed a Staff of Camo and right-clicked the face of one of the camo blocks. The server... crashed.
These are the crashes for placing a camo block [they are identical].
This is a crash for clicking a camo block with the staff.
Then I looked at the server log, and found this error. Hopefully, it might be useful.

Fixed in latest version