Hi , I had the same issue. Below are the steps I followed and it got resolved.
1.) C:\Users\XXXX\AppData\Roaming\NuGet → Removed NuGet.Config & nugetorgadd.trk
2.) Downloaded and installed Nuget.exe from NuGet Gallery | Downloads (after installataion Nuget.Config file will regenerate in above path)
3.) Reinstalled Uipath Community edition
4.) Opened the Xaml file. Thats it! It working now. Please try!