Msg 916, Level 14, State 1, Procedure <name> Line 0 server principal "sa" is not able to access the database "DBName" under

A typical error suggesting that user is unable to access the database within the security context, I would say it is serious one. Why I said typical at the beginning that it is not a regular error number you should see within the day-to-day stuff, a brief overview on BOL about the text reveals that when you run a TSQL statement to raise the DDL related actions such as trigger then youw will get such message. Also further to that note KBA913422 refers that this occurs when following conditions are...(<a href="http://sqlserver-qa.net/blogs/t-sql/archive/2010/06/30/9179.aspx">read more</a>)<img src="http://sqlserver-qa.net/aggbug.aspx?PostID=9179" width="1" height="1">