Generator issues

[Salmon Run]

Hello all, sure hope i can get some help on this one. 1998 Discover, propane Onan generator. Recently had my propane tanks filled and the gen started up as normal and then died and wouldn't restart. i tried the esd switch in both positions (on and Off) and no luck starting. My query is should the esd switch be in the on or off when running. Shoulds like a dumb ? but i want to be sure before i start bleeding lines, any other tips would be much apprieated.

[Mr Lars]

this may sound dumb, but did you check to make sure the valve on the tank is open?
the person who filled may have shut it off during the filling process, and failed to open when done.
does all the other propane devices work?

[Salmon Run]

i have a separate tank for the gen set and it's the esd switch that is used as a valve, that's why i was asking about it. there is a valve on the tank but your have to crawl under the unit to get to it and it has never been touched.