In addition to reviewing the pre-migration and migration report and log files, use these troubleshooting tips to help diagnose problems that you might encounter during or after the vRealize Automation migration process. Cleaning Up Migration Tables in Source 5.2 DatabaseThe source supported vCloud Automation Center 5.2 version database contains stale migration table data that is blocking the administrator from successfully rerunning the vRealize Automation pre-migration or migration task. Database Name Mismatch During Pre-MigrationA warning appears if the vRealize Automation database name you specify does not match the name in the Model Manager Web Service configuration file. User Principals Cannot be MigratedThe pre-migration report indicates that user principal names cannot be migrated or that domain trust issues exist between the source and target systems. Cannot Connect to Model Manager Web ServiceAn error occurs during pre-migration or migration if the source or target Model Manager Web Service is not available. Cannot Connect to Remote ServerAn error message appears during migration if the network is not available. Cannot Create Application Services ReservationAn error occurs during the vRealize Automation pre-migration task while creating an Application Services reservation for a business group. Model Manager Web Service is OfflineDuring the vRealize Automation pre-migration and migration tasks, the Model Manager Web Service must remain online in the source and target systems. Pre-Migration Fails with a Load Balancer Timeout ErrorThe vRealize Automation pre-migration task does not finish and the pre-migration log states that an aggregate exception error has occurred. This message may indicate that a load balancer processing operation has timed out. Migration Fails when Port Number is Part of Database Server AddressMigration fails with an MSBUILD error because the migration task does not recognize the port value that was specified during pre-migration. Migration Fails with a Wait Operation Timeout ErrorThe vRealize Automation migration task does not finish and the migration log indicates that a wait operation has timed out. Migration Fails with a RepoUtil Assembly Timeout ErrorvRealize Automation migration fails if the RepoUtil utility phase of IaaS assembly upgrade does not complete within the specified timeout period. Machines Not Visible on Items Page After MigrationAfter migration, migrated machines are visible using the Infrastructure tab but are not visible using the Items tab. Reservation Not Available After MigrationAfter migration, an error occurs during machine provisioning if the multi-machine blueprint does not have a transport zone value specified on the associated reservation.