Error occurred in deployment step 'Activate Features': Cannot start service SPUserCodeV4 on computer

Root Cause: Microsoft SharePoint Foundation Sandboxed Code Service is stopped.
Solution:
Open Central Administration site
go to System Settings
lick on Manage Service on server
Check to see if Microsoft SharePoint Foundation Sandboxed Code Service  is running, it should be stopped
Start the service and try deploying the Sandboxed solution