This is actually a bug in .NET shipped with Windows 10 1809 - when running in High Contrast mode, programs that aren't manifested as Windows 8-compatible .NET programs fail to open common dialogs with the following error:
COMException
Error: Creating an instance of the COM component with CLSID {DC1C5A9C-E88A-4DDE-A5A1-60F82A20AEF7} from the IClassFactory failed due to the following error: 80040111 ClassFactory cannot supply requested class (Exception from HRESULT: 0x80040111 (CLASS_E_CLASSNOTAVAILABLE)).
Ignore error and continue?
Da Ne
Workaround is to mark the executable as Windows 8-compatible in the manifest - this allows the program to run with visual styles enabled in High Contrast mode.
This is actually a bug in .NET shipped with Windows 10 1809 - when running in High Contrast mode, programs that aren't manifested as Windows 8-compatible .NET programs fail to open common dialogs with the following error:
COMException
Error: Creating an instance of the COM component with CLSID {DC1C5A9C-E88A-4DDE-A5A1-60F82A20AEF7} from the IClassFactory failed due to the following error: 80040111 ClassFactory cannot supply requested class (Exception from HRESULT: 0x80040111 (CLASS_E_CLASSNOTAVAILABLE)).
Ignore error and continue?
Da Ne
Workaround is to mark the executable as Windows 8-compatible in the manifest - this allows the program to run with visual styles enabled in High Contrast mode.