One or more files in the project have the /clr switch thrown on them, but the entire project is not built with /clr. The ...

One or more files in the project have the /clr switch thrown on them, but the entire project is not built with /clr. The /clr switch on the fil(es) has been converted to /clr:oldSyntax. You may have other compiler switches set that conflict with /clr:oldSyntax and will need to be changed before you can build successfully. Please see the help topic 'Managed Extensions for C++ Syntax Upgrade Checklist' for more information.