Verified in 5.4.5.2. After updating the appliance template to 5.4.5.2, spawning a VM and configuring the database, the UI appears to work normally, without any imminent errors as it was before. Tried adding and refreshing a vSphere provider to smoke test it and it seems to work O.K.
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://rhn.redhat.com/errata/RHBA-2016-0171.html