You need to try starting your SQL Service specifying Trace Flag 902 at startup. Or, you can try to bring SQL Server online and view the log in SSMS like you normally would. One way to do this is browse directly to the folder containing the SQL error logs and try to open the error log in notepad to get more detail on why the SQL instance will not start. In order to find out what’s really going on, you need to look at the SQL Server error log. I wish Microsoft would change this to something a little less terrifying, like “An error occurred during the patching process, see log for details.” But, they didn’t ask me… Next, Figure Out What Really Happened First, Don’t Panic!Īs I said, this error can be misleading.

The good news is, most likely this is a false error and the master database is perfectly fine. Actually, this seems to be the default error that Microsoft throws any time there is a problem with the patching process. This is not the first time I have seen this error. Restore master from a full backup, repair it, or rebuild it. It was throwing the following heart attack inducing error: Cannot recover the master database.

Recently, during patching for a 2019 SQL Server, the SQL services refused to start after the patching.

Rebuild master database in sql server