I'm testing 4.3 as an upgrade from 3.5.17 (well, from 2.10.3 actually but I need to go via 3.5.17).

The 3.5.17 to 4.3 upgrade & migration has finished, when opening the Notifications panel it throws a system error. I've enabled safe mode in UPM to rule out user plugins causing issues and it doesn't correct the problem. Oh, and ActiveObjects was never installed as a user plugin on this instance.

Cause:

com.atlassian.activeobjects.internal.ActiveObjectsSqlException: There was a SQL exception thrown by the Active Objects library: Database: - name:Microsoft SQL Server - version:09.00.3042 - minor version:0 - major version:9 Driver: - name:jTDS Type 4 JDBC Driver for MS SQL Server and Sybase - version:1.2.2 java.sql.SQLException: Invalid object name 'AO_9412A1_AOREGISTRATION'.
at com.atlassian.activeobjects.internal.EntityManagedActiveObjects.find(EntityManagedActiveObjects.java:153)

Log attached with full details (I cut out the individual AD user/group sync lines since I assumed that they will be irrelevant).