Error symbols in VS and Message Log

How I can fix this problem?

Maybe FInventoryStruct doesn’t have an == operator. Is it a USTRUCT?

That’s not the problem. Unreal Engine does not display errors correctly

That error does not come from Unreal Engine, it comes from the compiler and/or editor you’re using.
This looks localization related to me. What language have you set for your system? What language packs have you installed for your compiler and your editor?

In system and VS is set to Russian lang.

I imagine the compiler is confused by the language settings then, or perhaps (if you’re looking at this inside a tool other than the console) the tool that reads the output ends up being confused. (Looks like it might be VS Code, perhaps?)

I don’t know exactly how to solve that, but at least this might help you figure out how to work around it!