Cannot upgrade from mysql 8.0.34 to aurora-mysql 8.0.mysql_aurora.3.04.1. Specify a current active database version, the latest active minor version for mysql 8.0 is 8.0.35.

To add to Regina's:

Aurora MySQL version 3.05 does not support migrating from some older MySQL 8.0 versions like 8.0.11, 8.0.13, and 8.0.15. The documentation recommends upgrading to MySQL 8.0.28 before migrating.

Even though the error message mentions 8.0.35, it's possible the underlying issue is still related to migrating from an older incompatible version. I would double check the actual MySQL version on the source instance.

Minor version upgrades can sometimes cause compatibility issues, even within the same major release. It may be better to avoid upgrading just the minor version and instead upgrade to a newer major release like 8.0.28 as recommended.

If upgrading isn't an option, another approach would be to take a snapshot of the source database, restore it to a new Aurora MySQL cluster, and then use that as the target of the migration rather than trying to migrate directly.

Checking the AWS documentation thoroughly for specific version compatibility between your source MySQL version and the target Aurora MySQL version being migrated to can help identify potential issues.

If you need to migrate asap, I could say there is another approach. It is to use a database migration tool like AWS Database Migration Service to migrate the schema and data independently of the instance itself. This bypasses the version compatibility check. You could take a snapshot of the RDS instance, restore it locally with the same version, and use a tool to migrate the data/schema to a new Aurora cluster.