When you get the above error please verify the event viewer once and below would be possible errors from event viewer.
Cannot recover the master database. SQL Server is unable to run. Restore master from a full backup, repair it, or rebuild it. For more information about how to rebuild the master database, see SQL Server Books Online.
(or)
Script level upgrade for database 'master' failed because upgrade step 'SSIS_hotfix_install.sql' encountered error 942, state 4, 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.
Possibilities :
1. Check if any system patches or SQL Patches applied. For me SQL 2012 SP2 is applied the day when I have faced this issue.
Resolution :
NET START MSSQL$instancename /T902
Cannot recover the master database. SQL Server is unable to run. Restore master from a full backup, repair it, or rebuild it. For more information about how to rebuild the master database, see SQL Server Books Online.
(or)
Script level upgrade for database 'master' failed because upgrade step 'SSIS_hotfix_install.sql' encountered error 942, state 4, severity 25. This is a serious error condition which might interfere with regular operation and the database will be taken offline. If the error happened during upgrade of the 'master' database, it will prevent the entire SQL Server instance from starting. Examine the previous errorlog entries for errors, take the appropriate corrective actions and re-start the database so that the script upgrade steps run to completion.
Possibilities :
1. Check if any system patches or SQL Patches applied. For me SQL 2012 SP2 is applied the day when I have faced this issue.
Resolution :
NET START MSSQL$instancename /T902