After Upgrade from 8.20.12 to 8.20.14 the Jira is not able to connect to the database Need solution

[Suresh Kumar]

We Recently have upgraded our Jira Datacentre version from 8.20.12 to 8.20.14 the Jira is not able to connect to the database. The error message the posted below.

Database: Missing Database Driver

We couldn't find a driver for your MySQL 5.7 database. You'll need to download and install the correct driver to allow JIRA to start and connect to your database.
Review our documentation for more information on installing database drivers.

Before some one comments:

we were using the dbconnector 5.1.47 and these is not helping and our MYSQL database is 5.7.38 database engine. 

we tried to different db connector like 8.0.11, 8.0.22 and other versions but we are getting the same error.

the DBCONFIG file is having the correct values as per the atlassian suggestions.

can some experts throw some light and help with a suggestion.

[Suresh Kumar]

The issue was solved. as one of the dataabse connector file was corrupted.

[Nic Brough -Adaptavist-]

When you do a Jira system upgrade, it can remove files that you may have added to the previous installation, but I would not expect this upgrade to have done this.  You have done exactly the right thing - checked the compatibility and tried the drivers Atlassian explicitly state they support.

I would want to check 

• The dbconfig file with a "fine toothcomb" - only the driver related settings - are you sure it is looking at the right driver?  Or, better, just using (the only one you make available)
• Are the permissions on the driver files correct, and of course, are they in the right place?
• Is there more than one driver in the directory?  If so, can you chop it down to only the one you want to use (latest 8.0.x recommended)

[Suresh Kumar]

Hi,

when we downgrade with the same version its working fine but when we upgrade its failing yes we tried all available versions but nothing working out all the permissions are correct and working as expected.

Thats what i even deleted the file and downloaded the new file and pushed to the location and tried doing the same

[Nic Brough -Adaptavist-]

We can't help you with this - there is something wrong in one of the three areas I talked about, but without seeing everything, we can't tell you what is wrong.