Services not coming up after SP4 upgrade SQLSERVER 2012

Hi Gurus

Please help me resolve following error. after imstalling SP4 on SQLSERVER 2012 i'm not able to start the services for server and agent and i found the below mentioned error in the logs for sqlserver.

"Script level upgrade for database 'master' failed because upgrade step 'msdb110_upgrade.sql' encountered error 2714, state 6, severity 25. This is a serious error condition which might interfere with regular operation and the database will be taken offline. If the error happened during upgrade of the 'master' database, it will prevent the entire SQL Server instance from starting. Examine the previous errorlog entries for errors, take the appropriate corrective actions and re-start the database so that the script upgrade steps run to completion."

Thanks in advance

Searching for the error code/state/severity brought me to this page; you might want to review the description there, and/or other Microsoft support info.

I am not familiar with the error, so there is nothing more I can offer.

Thanks James for your quick responce