Debugger not auto-detected

Windows offline installer qt-enterprise-windows-x86-5.9.4_918.exe, install for example msvc2017 x64 binaries and launch Creator.

Open any project (or create new), go to debugger mode by clicking the debug button on the left side. Click start debugging button -> dialog opens (see screenshot win_debugger_fail) "The selected debugger may be inappropriate for the inferior.." and debugger is not starting. Application output has:

Unable to create a debugging engine. Please select a Debugger Setting from the Run page of the project mode.

Tools-> options -> Build & Run -> Debuggers shows no autodetected debuggers. I have been using debugger in this same enviroment and it has been working (just can remember when it was used last time..)

On some occasions whole installation gets corrupted: open any new project, when help window is opened Creator crashes. Even if AppData/Roaming/QtProject folder is deleted, Creator will always crash on opening the help window on any of the projects. Only way to recover is to uninstall and re-install from scratch.

Reproduces with QtC4.5.0 built with Qt5.9.4, From revision b984400f2d

Does not reproduce with QtC4.5.0 built with Qt5.10.0 from online repository.