The problem relates to the the sequence value being duplicated for the plugins table.
Test the solution in a development environment prior to implementing in production. The provided solution may for each vary slightly depending on the JIRA instance.
Find out the highest sequence value in the pluginversion table. This can be achieved with the following query:
It should yield similar results to this:
Increase the table's sequence value to be higher than the highest ID number in your instances table. In this case the highest number was '10051', so to be safe the Sequence ID should be updated to '10070' to give a slight buffer. This can be accomplished through the following query:
Keep in mind that that the max ID may differ between each JIRA instance. Modify the SEQ_ID number to be higher or lower as needed, but it should always be higher than the max ID in the pluginversion table.