Although it can save you a lot of time, the Version & Component Sync add-on can also be very destructive in case the add-on is not configured properly. The Version & Component Sync add-on will alter the linked project version configuration as soon as the link has been created. This can include deletion of versions, which also removes them from any associated issue.
Even though we have an extensive set of automated and manual tests that are executed each release it is highly recommended to make a full back-up of your installation. If possible, install it on a non-production JIRA instance prior to using it for testing purposes.
Make sure you are fully aware of how the add-on configuration works and that you have confirmed that it is configured and working as expected.
CollabSoft will not accept any responsibility in regard to the data integrity of your JIRA instance.