The on line ArcGIS help says that the solver may not find the solution and fail. When can that happen??
I mean in the first case the solution follows the 5th hierarchy then converts to 4th then 3rd then 2nd then goes to the 3rd again then again to the 2nd...why if the Hierarchy is checked on!!??
(the solver descends and ascends when the hierarchy button is on!!!). Shouldn't it have failed??....
.... and the when we have the same start and end points and only add some barriers the solver shows an error. Why it cannot descend and ascend this time??
When I uncheck the hierarchy (in the example with barriers) the solver responds giving a solution.