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When I try to deploy my custom wsp solution to a specific web application, I got the error below:
This solution contains no resources scoped for a Web application and cannot be deployed to a particular Web application.
The error message itself explains why you cannot deploy the solution to a web application. However if you do not like to deploy the solution to all the web applications and only like to deploy your solution to a specific application , you need to change the solution settings Assembly Deployment Target from GlobalAssemblyCache to WebApplication.
After you change the Assembly Deployment Target and run the script again, you will have the solution deployed successfully.