There are a number of references to this error, all related to the use if linked servers and how SQL Server handles loopback calls.

http://sqlblog.com/blogs/linchi_shea/archive/2009/12/18/the-transact-sql-prime-directive-a-bad-example.aspx

https://social.msdn.microsoft.com/Forums/sqlserver/en-US/13b6fa12-13a2-41e1-a581-3295adbccf69/transaction-context-in-use-by-another-session

There are more, Google this.

The thing that throws me about this error is that the spid is 11, which is a system SPID.