Upgrading JEM from 4.0 to 4.2 fails

Upgrading JEM from 4.00 to 4.2.0 fails.
Error message is as follows.
JInstaller::Installation:Error SQL Duplicate column name 'requestanswer'
Extension installation has been interrupted.
Package Update: Error installing extension: com_
An error occurred while updating the package.
Joomla : 4.4.4
PHP : 8.1.27
Please teach me how to solve or avoid the error.
Thanks,

Please try:(sometimes this helps) use repair button database then install again.

Where is repair button for database? What does repair button do with database?
Regards,

Backend>Maintenance>Database>Repair
If this doesn't help please search in this forum. Such cases during migration were just discussed!
Jojo