Board Thread:Bug Reports/@comment-26274215-20160903162538/@comment-27219153-20160903173916

The crash is being caused by rendering your player entity in the inventory screen. The most likely cause of this is one of these mods: Xray, Optifine, MorePlayerModels. Since you said it didn't happen immediately when playing beta 29, It's likely that you changed your player model and changing it back to what it was would probably work. If its not one of those mods, then just remove other mods one by one until it doesn't crash.

Also, your allocated RAM is a bit low and I would recommend increasing it to 2G if you have enough physical RAM to do so. Your forge version is quite old, I would recommend updating to either the one ending in 1291 or the latest recommend which ends in 1558.