[19:22:21] [Client thread/ERROR] [FML]: The mod primitivecrafting is expecting signature 55e88f24d04398481ae6f1ce76f65fd776f14227 for source PrimitiveCrafting-1.12.2-1.4.1.jar, however there is no signature matching that description
Just wanted to let you know.

Yes, haven't gotten around to fix it, just ignore it

Should no longer be an issue on latest versions