Hello,

A website that has been working fine on Umbraco V7.1.4 has suddenly become quite slow running and the administrators keep getting the following error message when trying to view the Media section.

Failed to retrieve data for application tree media

I have checked the trace log and can see entries such as follows:

15:07:29  INFO  Umbraco.Core.Persistence.UmbracoDatabase 
  at System.Data.SqlClient.SqlConnection.OnError(SqlException exception, Boolean breakConnection, Action`1 wrapCloseInAction)
   at System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj, Boolean callerHasConnectionLock, Boolean asyncClose)
   at System.Data.SqlClient.TdsParser.TryRun(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj, Boolean& dataReady)
   at System.Data.SqlClient.SqlDataReader.TryHasMoreRows(Boolean& moreRows)
   at System.Data.SqlClient.SqlDataReader.TryReadInternal(Boolean setTimeout, Boolean& more)
   at System.Data.SqlClient.SqlDataReader.Read()
   at Umbraco.Core.Persistence.Database.<Query>d__1c`1.MoveNext()

The developer console in Chrome shows an issue with the following URL:

/umbraco/backoffice/UmbracoTrees/ApplicationTree/GetApplicationTrees?application=media&tree=&isDialog=false

and if I click this the following is returned:

)]}', {"Message":"An error has occurred."}

I have taken an exact copy of the website and database back to my development server and it all works perfectly fine??

Does anyone have any idea what might be causing this very random issue or be able to help me in determining what the cause might be??

Thanks,

Graham