QC lost settings

Not sure if reproducible:

• worked a couple of days with a 4.14 snapshot (409) - separate settings
• updated to a newer snapshot (411)
• started QC with the settings I've used with the former 4.14 snapshot
• tried to load a session
• could not re-open project due to no valid kits

Observations:

• no Qt version (had these manually configured, not linked to Qt) [probably a - from my side unexpected - Qt detection?]
  (all following seem to be a result of this..)
• my main Kit has been re-created "Replacement of..." - but no Qt (and resulting in no compiler as well)
• MinGW Kit got a different MinGW (one present in Perl which I think I had removed with the former snapshot, but 2 other MinGW are still present (from Qt installation))
• other kits present before have been re-created with defaults (compiler fine, no Qt)