PHPBB Forum Migration and Error Fix

I need assistance with migrating a PHPBB forum from one server to another, hosted by different providers. The new server already has PHPBB installed with a new database, but I'm encountering numerous errors when attempting to restore from backups. I have both data-only and full backups from the old server, and all extensions were disabled prior to creating these backups. The goal is to complete this migration by the end of the month.

Key Requirements:
- Successfully migrate the PHPBB forum to the new server.
- Resolve any errors encountered during the restoration process.
- Evaluate whether to maintain the current PHPBB installation on the new server or replace it with the old forum setup.
- Ensure that the forum is fully functional and all data is accurately restored.

Ideal Skills and Experience:
- Extensive experience with PHPBB forum migrations and troubleshooting.
- Strong understanding of database management and server configurations.
- Ability to work with both data-only and full backups.
- Problem-solving skills to handle unexpected errors during the migration process.
- Good communication skills to provide updates and recommendations.

Please help me ensure a smooth transition and restore the forum to full functionality.