According to following link: Upgrading Guide – “In production environments a exact valid redirect URI without wildcard needs to be configured for any URI of that type.”
The upgrade from v23.0.6 to v24.0.3 seemed to have failed - The test: attempting to access the admin console (a blank page remains). There are no log entries pointing to potential cause (despite setting log to DEBUG).
Wondering if could be the ‘Valid redirect URI’ setting in screenshot below (containing a wildcard):