An ambulance was dispatched and had 2 crew assigned to it. Upon arrival at the scene it didn't provide patient care, so upon investigation it said it had 0 crew. I then looked at the crew at station, and it said the crew was available and not on a call, even though their assigned Ambulance was out at a call. I canceled the Ambulance with no crew and dispatched another one and it worked fine. This is a strange issue because it is a 1 time thing, on 1 Ambulance.
The issue was only earlier tonight( 4/16/2017 @ 2129 -0400 UTC )
Again, this is a strange issue, and don't really think there is a way to fix the problem, because there probably no way to diagnose the problem. Best of Luck.