Plugin Build fails only on UE5.4

Greetings @YobiRobert

Welcome back to the Unreal Engine Community Forum! I’m not 100% sure if this is the problem. But, the first line of error you posted ‘error C2144: syntax error: ‘int’ should be preceded by ‘;’’ is something I’d start with. I had this same error once and couldn’t compile because I didn’t add the ‘;’ to my header file. I’m not sure that’s the same scenario here. But, I’d start with that error first.