Issue

The plugin has been installed in JTL 3. The shop version is migrated to version 4. However the plugin is not compatible with JTL 4. As such the migration is not allowed to be executed.

Resolution

The plugin has to be deinstalled. The data will not be removed. The tables with the transactions will remain in the database. Once the base shopping cart has been migrated. The new version of the plugin (from the folder files_4.x) has been uploaded the plugin can be installed again. Any required migration will be triggered within this step.