Model Save Error "Invalid Class"

[Maxwell Cameron Jones]

I have been using DWSIM for a few weeks work through tutorials exercises, all functioning fine. Then suddenly now not able to save models.

Instead the following message occurs, see screenshot attachments : SaveAs error
Error saving file:System.AggregateException: One or more errors occurred. ---> System.Management.ManagementException: Invalid class

Save Error , window "An unhandled error was raised" , Error message "Invalid class"

I have uninstalled the program and reinstalled but the error persists.
Is anyone able to help me with this error ?

[Daniel Medeiros]

It seems to be something with your computer as the error is coming from inside the Microsoft.VisualBasic library, not from DWSIM libraries. This error is happening when DWSIM tries to get the Operating System name.

[Maxwell Cameron Jones]

Thank you Daniel M, for the insight. I was able to find the solution on how to fix the WMI Class error. See following instructions and link.

Repair Instructions
http://thewindowsupdate.com/2019/03/16/wmi-missing-or-failing-wmi-providers-or-invalid-wmi-class/

Provider details
https://docs.microsoft.com/en-us/windows/win32/cimwin32prov/win32-processor

[Priyam Nayak]

Can you please point out the steps you followed to resolve the WMI class error? There are too many steps mentioned in the link you gave and I am not able to follow properly.

[Daniel Medeiros]

Try this, Priyam: https://www.thewindowsclub.com/how-to-repair-or-rebuild-the-wmi-repository-on-windows-10

[Priyam Nayak]

Daniel, while running the consistency check for WMI repository, I got the message that WMI repository is consistent. I am attaching the error message I get while trying to save the file.

[Daniel Medeiros]

https://github.com/yenpuren/WMI-Fixer-Tool

[Jyotirmoy Roy]

Its still showing error and on rnning the poweshell with Yes option showing :"Credential Elevation Required"

[Serhii Krushnevych]

It needs to change the ExecutionPolicy (if needed) and run the PowerShell console with Administrator privileges.
ExecutionPolicy change to Unrestricted PS command:
Set-ExecutionPolicy

Today I received the same error "Invalid Class..." while saving the file.
Tried to manually fix it by winmgmt, but it shows "all OK". Only the WMI-Fixer-Tool helps.