If you still have Creativerse in your Library (and if you don't see it, check if by chance it's hidden) then try as follows:
- check the game properties on Steam, there should be a DLC section, there you should see the TDE DLC, if it's not selected to be installed, select it
- try validating / reinstalling, sometimes Steam downloads the obsolete promo applet asking players to buy, but that should be replaced by the TDE DLC installation if the player has Creativerse in their library

If none of the above works let me know (just reply here in this thread) and I'll add your profile to the manual granting queue, may need a few days for the operation to be performed.

Also, if you're interested in a copy of the worlds you had on our servers please either email support@playfulstudios.com or DM me on Discord - entuland#7134

As a sidenote, worlds are now self-hosted by players, saves are only stored on the computer that runs the world, so it's up to the players to keep backups of their worlds in case of need (say, reinstalling, moving to another computer and so forth).