I experienced a server crash on my single-player world after breaking a vanilla glass block in survival. The glass was not stained, and was not a pane.

I took the glass block from the creative menu. I then placed it down in survival and broke it.
The world seed was 1970628762, and the worldgen type was Flatlands.

I think this crash might have something to do with the mod's 'glass shard' item not dropping properly.

Here is a pastebin link for the server crash log : http://pastebin.com/kqZ00DjJ

On it

Fixed.