The following is a sequence of steps to perform if you're asked to fully uninstall/reinstall Gliffy.
Please note: all of your Gliffy diagram data will be preserved throughout this process (diagrams are stored as attachments on Confluence pages).
1. Uninstall the Gliffy Confluence Plugin using the Confluence UPM (in Confluence Administration --> Add-Ons).
2. Stop/shutdown Confluence.
3. Delete (or move away) the following directories:
These directories will be automatically recreated when you restart Confluence.
4. Delete the plugin from the database by executing this query:
DELETE FROM plugindata WHERE pluginkey = 'com.gliffy.integration.confluence';
5. Delete the plugin license from the database by executing this query:
DELETE FROM bandana WHERE bandanakey like 'com.gliffy%';
7. Restart Confluence.
8. Reinstall Gliffy by using the UPM, and re-enter your license key.