Error: trouble in init_rank virtual 18 virtual 4 virtual 6 ...
Curiously, the error can be eliminated by changing the weighting on a particular edge
"184.108.40.206" -> "3.4.1" [label="Step Back", weight=7];
between 7 and 12. A number outside of these values causes the error to return. Could it be that setting the weighting for the edge to particular values reduces (or possibly increases) the number of possible layouts/routes, such that it works or doesn't work?
Input file: b1164.dot
There is a workaround of sorts - by changing the weighting number for the edge. However, I don't know how you figure-out which edge to adjust or what weighting value to use (except by trial and error).