Oops, skipped a database conversion!

SOLVED

We've skipped a database conversion during multiple upgrades (2017 to 2021), and now the database shows as "incompatible" and cannot be converted. The recommended solution is to get Professional Services involved. I'm wondering if I could start over with 2017. I took a backup of the data before starting all this. Could I un-install the 2021 version of Fixed Assets Server - Network from the server, and install the 2017 version, then restore the backup, and start the upgrade process again?

Thank you for any input on this.

Richard