In a SharePoint 2010 Sandbox, Central Administration and other SharePoint sites threw an error: 403 FORBIDDEN
Verified Site collection Lock settings, IIS Settings (IP, Host name, Bindings) other permission settings. After a while found SQL Server services are in Stopped State from SQL Server Configuration Manager. Tried starting them. After a while got an error message: The request failed or the service did not respond in a timely fashion. Consult the event log or other applicable logs for details.
So it gave me a clue to look into event viewer. Why don’t I give a try to look into event viewer? Let me do that. Found multiple events with 7038 logged in the event viewer. Hmm. Here is the issue root cause.
The root cause for 403 forbidden error in SharePoint (2010 or 2007):
The event viewer clearly tells Logon failure and Password Expired. Gotcha! Due to Active Directory’s Group Policies, password for the SQL server’s service account has been expired automatically. So HTTP 403 forbidden error in SharePoint occurred due to SQL Server failure!
What is the fix? Simple! Changed the Password for the service account in which SQL Server run, Updated the password for SQL Server Services, Tried starting the services again, It worked!
Tail: This issue may happen when the SQL Server’s port (by default it would be 1433) used by some other program.