When I start the server it gives me this error: MissingFieldException: Field 'ProtoBuf.Sign.imageIds' not found. and then the servers just stops the starting process and I honestly have no clue what that means. Anybody knows something about that?

Do you have both an up to date Rust and Oxide version? This could be caused by mixing versions.

I have an update script, so yeah both are probably updated.

The error means you are mixing Rust versions, so you aren't fully updated.

How can I make sure that it fully updates?

Quapi

How can I make sure that it fully updates?

By manually verifying the version before and after installing Oxide.