After upgrading both VS and AI, the aip project refuses to load in visual studio. I removed and re-installed the plugin (which is still 18.9 in the marketplace) and this not help. The project does open and build correctly when launching AI against the api file manually outside of Visual Studio.
C:\Source\xxxx.aiproj : error : Retrieving the COM class factory for component with CLSID {478E872F-CA78-459B-9382-F2A25A255C37} failed due to the following error: 80040154 Class not registered (Exception from HRESULT: 0x80040154 (REGDB_E_CLASSNOTREG)).
I am attaching a (renamed) project aiproj file.
In poking around I did notice the the aiproj file does have a couple of elements not included in the msbuild/2003 schema referenced (ProjectHome and Private). Possibly not related to the issue, but maybe?