Predefined types not found (or imported)

[kopbeen]

Good afternoon,

A bit stumped with this one :

System.void , System.Inptr, System.Object not defined or imported... a bit stumped with this one....

 

[VBService]

Sometimes the SDK or project files can get corrupted. You could try cleaning and rebuilding your project.
Use the following commands in the terminal/command prompt:

dotnet clean
dotnet build

If the issue persists, try reinstalling the .NET SDK.