"Error occurred in deployment step ‘Activate Features’: Cannot start service SPUserCodeV4 on computer "
If you ever try to deploy a sand boxed solution and run into Error occurred in deployment step ‘Activate Features’: Cannot start service SPUserCodeV4 on computer, this only means that the Windows service running sand boxed solutions is not running on the server.
To start the service go to SharePoint Central Administration, go to System Settings tab and click on Manage services on server:
That’s all! Your solution should deploy just fine now.
If you have a more elegant solution – please post a comment…