When crafting items that use a tool that takes damage upon crafting (in this case, an Immersive Engineering hammer being used to make Immersive Engineering plates) and the tool reaches the end of its life, the workshop crashes with this error instead of removing the damaged tool.

http://pastebin.com/Hqstm21D

EDIT: this works fine in a vanilla crafting grid.

Thanks for the report. I will look into this issue.

There is not much we can do about this ATM, it's an issue with how IE handles crafting with it's hammer. The table works fine with IC2's and TiCon's items.