See the attached diff screenshot. The problem occurred when I edited a .h file that had a Q_OBJECT macro in it and saved. It does NOT occurr, when the AddIn is disabled. I've been having this problem since at least 2.1.0... If I could create a minimal example, I would, but it seems to only happen on rather large projects. A lot of our configuration is done through .props files, so maybe that is a part of the problem.
EDIT: This does happen reproduceably when SAVING. It does not matter wether I add signals or slots. I added a simple non-virtual method to the header file.
I skipped through the DocumentSaved() function in http://code.qt.io/cgit/qt-labs/vstools.git/tree/src/qtvstools/DteEventsHandler.cs and it might have something to do with the "hasDifferentMocFilesPerConfig" flag or the config not being read correctly, as we have different GenerateFiles folders per configuration...