How to Start Sandboxed Code Service on SharePoint server 2010,2013 and 2016.
The steps to start the Sandboxed Code Service on a SharePoint server 2010, 2013 and 2016
1 Login with SharePoint Admin in SharePoint server Machine and then go into the Central Administration.
2 Under System Settings, Click on ‘Manage services on server’.
3 Click on Start ‘Microsoft Foundation Sandboxed Code Service’.
4 Open the Command Prompt and Restart IIS service (by IIS reset command).