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Could you please provide us with the exact log of the error you are facing? Also, is the error happening when you start Jira or is it in any other specific step?
Since database errors can be caused by several reasons, we can not provide you many instructions without the logs of the error but to try to configure a new server instance (8.8) from the very beginning and upload the backup file from your current instance to the new one, checking if the error persists.
We will be waiting for the logs of the error to provide you with more specific steps that might help.