Hello,
You can activate the license twice: once for productive and once for the final stage, you can run two of these sites to test something.
The problem was caused by incorrect site transfer, please try this free plugin: All in One WP Migrate, if your site is the big size you will have to upgrade to the Pro version. I do hope you have the backup and you can try again and this attempt would be succeful.
This plugin transfers sites easily and correctly.
Best Regards