[Richard]

Let me take a shot at summarizing the symptoms so that someone in the future may get to a diagnosis much quicker than my own experience, and the experience of other owners.

Engine dies for no apparent reason.
No error codes on DDEC.
CEL and SEL lights on dash, light up, and go off when key is switched on. This tells you the DDEC is getting power and functioning well enough to start the engine.
Examination of the fuel filter shows one of two things:
Fuel all the way up to the top of the clear bowl. The filter is plugged. Change the filter.
OR No fuel is visible in the clear bowl.
If no fuel visible in the clear bowl. Remove the vent cap on top and fill with clean diesel or ATF.
If engine starts, stumbles, and dies again. Observe the level in the bowl. If it disappears again, there is a problem somewhere between the fuel tank and the fuel filter.

It could be a number of things:
Fuel hose, or fittings, or gasket at fuel bowl is leaking air. Fill with fuel again, and look for air bubbles when running.

Of course try new fuel filter and gasket. Assuming that doesn’t fix it, the other diagnostics are not going to happen on the side of the road. You need to get to safety and avoid a tow if at all possible. This will be ugly, but use a hose from the tank to the fuel filter. Fuel hose is best, garden hose will work. Cobble fittings on one end to mate with the inlet on the fuel filter. Run the other end into the tank inlet. Zip tie it all in place. It is not an easy task to run the hose over the tank and through the coach to the fuel filter. So run it outside the coach. You will have to figure out a way to prime the hose. Vacuum guns work, transfer pumps (aka Harbor Freight) work, wouldn’t recommend Georgia credit card unless diesel is a preferred mouthwash. When you run the engine out of fuel, it will take a number of extended cranks to get fuel to the injectors.

You will feel like Jed Clampett, but this will get you to safety.