MIDL error: ‘annotation’

A colleage recently got this error while compiling unknown.idl:   1>C:\Program Files\Microsoft SDKs\Windows\v6.0\Include\unknwn.idl(108) : error MIDL2025 : syntax error : expecting ] or , near “annotation”1>C:\Program Files\Microsoft SDKs\Windows\v6.0\Include\unknwn.idl(108) : error MIDL2026 : cannot recover from earlier syntax errors; aborting compilation   If you get this error, you are using a new version of the Windows headers…