How to fix the Oracle error ORA-01617: cannot mount: string is not a valid thread number?

In this post, you’ll learn more about the Oracle ErrorORA-01617: cannot mount: string is not a valid thread number with the details on why you receive this error and the possible solution to fix it.

Oracle Error Description

ORA-01617: cannot mount: string is not a valid thread number

Reason for the Error ORA-01617: cannot mount: string is not a valid thread number

The INIT.ORA parameter “thread” is not between 1 and the number of threads allowed by the control file.

How to fix the Error ORA-01617: cannot mount: string is not a valid thread number ?

You can fix this error in Oracle by following the below steps

Shut down the instance, change the INIT.ORA parameter and startup, or resize the thread record and/or checkpoint progress record sections of the control file.