We need to know if you are using the old or the new project system. Does your project show in the solution explorer with the text "(Arduino)". For example:- "MyProject (Arduino)"

Thanks, when you create questions in this forum please follow the guide in yellow at the top of the page.It avoids us needing to ask lots of questions.

Assuming you are on a recent version of Visual Micro, there is "Convert" option on the toolbar and also on the vMicro menu. That will convert your .vcxproj to the newer intellisense engine.

The old system could easily produce those false errors. It was often depedant on the specific platform version and also used microsoft VC++ project format that did not understand some underlying GCC. The newer format uses the new Microsoft project format for Embedded systems which unserstands GCC.

Reminder: don't forget the requested output when creating threads in thi forum