Illegal characters

Hi guys.

I have a bug where Designer.exe can not be opened in VS even if you can open it manually from the bin folder.
The bug that is shown is always 'Illegal characters in path." even if this really means that the designer.exe is not found and can not be opened.

Now Qt 5.15 was build to D:\SDK\Qt\5.15.0\x64. qt.conf set to D:/SDK/Qt/5.15.0/x64/qtbase,
new Qt version was successfully added to the 'Qt Options' and build is working properly.
But if you try to open the designer the tools tries to open "D:\bin\designer.exe" instead of "D:/SDK/Qt/5.15.0/x64/qtbase/designer.exe".

Video about the environment and the issue:
https://1drv.ms/u/s!AulAg7BeKIMXgrV5S8er26un4TEMeA?e=fPcIrs

Process Monitor:
13:28:34,2005965 devenv.exe 21140 QueryOpen D:\bin\designer.exe PATH NOT FOUND 

If you need any other tests, please ping me and I'll do it.

Br
Waldemar