MSSQL Server Custom Functions Error on the Status Report page

This primarily relates to the lack of a REGEXP operator in SQL Server. IIRC Drupal Core supports the REGEXP operator and technically requires it, however does not use REGEXP itself. However, some contrib modules might make use of it, so some sites may experience problems with any such modules if they don't have a CLR installed to provide a REGEXP function that the module can use. I think downgrading it to a warning instead of an error would be reasonable.

That makes total sense. Showing it as an error throws "non-technical" people off in the management. Downgrading this to a warning would be a good step in the right direction.