In version 9.3.0.1, if you type in an incorrect user id or password, the error displayed is "No Engines Available in the Metastorm BPM Server Service".
This makes it extremely difficult to diagnose the reason, and causes an unusually large number of support calls from our customers claiming that their system is down, which is typically the highest possible severity.
All in all, it looks really bad to customers, wastes everybody's time, and will inevitably mask real issues when systems are down.