A compilable solution, at least two projects PA and PB, a type TA from PA used in PB. Add an interface IA to the TA's implementations list, such that it's defined in a DLL not referenced by PB. SWA correctly detects errors in all the files from PB using TA, as they mention IA from a DLL that's not referenced in PB. When I add a reference (via QFix), only the current file gets updated, but all the other files in PB still indicate an error.