In the 1.12.2 game version, Optifine_1.12.2_HD_U_G5 version.

If the quasi -star facing the top or bottom when using the spleen calamus, it will lead to the following situation:

Invalid Move Player Packet Received

Or

I received a packet containing illegal players' movement

This is a very serious problem!If you are a single model, this will cause your archive to no longer enter.

Solution: ESC → video settings → performance → fast operation (level)

In short, shutting down fast operations can be solved.