Installation issue ?

We just tried to install SigmaStudio for the first time on a machine with the latest Win10 / Pro / 64bit (german language).

(using the default path c:\Program...)

Everything seemed to go well. (Installation as administrator)

But with SigmaStudio started the tree toolbox is empty and when trying to create a New Project, a long list of errors occure:

"Could not find file C:\Users\....\Design 1 at system.IO_Error.WinIOError(Int32 errorCode, StringmaybefullPath)"

and lots of other System.IO-Errors...

It seems as if SigmaStudio tries to write a file and Windows does not allow it.

I tried running the Studio as adnministrator but with no success.

I can create files in the named directory "by hand" with no problems.

Tried it with version 4.5 and 4.6... both with the same problem

Windows reports Microsoft.NET 4.8 as installed.

What could be the problem ?

Thank you