Recently I started testing out SharePoint Online solutions. Its really hard to develop a webpart and test and debug it on Online itself(Because you need to upload solution, activate manually again and again). So I am using my SharePoint server installation and deploying my custom development as sandboxed solutions and then debugging them. When the webpart looks good I go deploy it on SharePoint Online.
When I created my first sandbox solution and try to deploy through Visual Studio 2010 it prompted me with an error.
Error occurred in deployment step ‘Activate Features’: Cannot start service SPUserCodeV4 on computer ‘KAMILSP2010’.
So I figured out this is something to do with missing of a service that needed to deploy or run any sandboxed solution. Little bit of googling helped me to sort it out the issue.
To resolve this you need to navigate to
SharePoint Central Administration –> System Settings –> Manage services on server
then search for the service “Microsoft SharePoint Foundation Sandboxed Code Service“ and start the service.
Then tried the Visual Studio deployment again, all went fine.