Dot Net Core 3.1 - I cannot Open/Edit any Form

[Cezar]

When I try to open any Form to Edit, the Editor Crashs with this error :

What I can do to fix it?
Before this I was getting some Syncfusion Licensing Error WHILE editing the Form.

[Mohanram Anbukkarasu]

Hi Cezar, 

Thanks for contacting Syncfusion support. 

We are little unclear with your statement “open any Form to Edit”. We suspect that you are trying to open the form designer to add/remove controls to it. Dot Net Core projects doesn’t have support for designer and toolbox in WinForms. It is not possible to open form designer in .Net Core projects. 

Kindly revert to us with details if we have misunderstood your requirement.  

Regards, 

Mohanram A.