Some mod is sending Thaumcraft an IMC message with an

ItemStack

that has a

null

Item

(i.e. the mod created an item stack, but didn't specify what it's a stack of). This is message is either telling Thaumcraft to allow golems to harvest a crop or to prevent the Lamp of Growth from growing a crop.

 

Unfortunately the crash report doesn't say which mod sent the message, so you'll have to narrow down the cause yourself based on the information I provided above and report it to the mod's author.

 

First try removing any Thaumcraft addon that adds crops.

This is still the same error.

 

You haven't disabled every Thaumcraft addon. Automagy, Thaumic Tinkerer, Magical Decorations and Tainted Magic are still enabled.

 

If you disable these mods and the error persists, try looking for other mods that add crops.

Thanks for the heads up on the other Addons. I've disabled those, along with agricraft and pams harvest (and nether addition). This resulted in a proper result, but the mods worked in harmony for about a week prior to having any issues (this includes the last issue I had with LatMod). Through the process of trial and error, I've isolated as pam's harvest the nether to be the culprit. I installed it about five days ago but never had a problem until now. I'm not sure why this happened, but I'm glad the issue has been resolved. Thank you again for your assistance, and good day friend.