VMware has issued an alert that vCloud Director users should NOT upgrade to 5.5, if they are using Microsoft SQL Server 2005 Service Pack 4 as their database.
If you attempt to upgrade the process may fail and you will see an error similar to:
Exception in thread “main” java.lang.IllegalStateException: java.sql.SQLException: Cannot assign a default value to a local variable.
The VMware support team is currently looking into this issue and will hopefully swiftly issue a fix.
You can follow their progress in KB article 2060068.
You could also upgrade your SQL server database to a newer version.
Supported database softwares can be found in the compability matrix.