I have just built & uploaded ViEmu/VS 2.1.23, which fixes some problems with F# language files in the presence of Visual Assist. Yes, the VS ecosystem can be quite complex at times, but I always try to address incompatibilities as soon as possible.
You can download it from here:
Be sure to manually uninstall the previous version before installing this one. I have also promoted this build to the ‘official’ build downloaded from the main download page, so you might already have it if you downloaded it from there.