That’s weird. As soon as you start Elite for the first time it should auto-generate an Elite folder, with that map.dat file in it. If it did not, something went wrong.
How did you unlock Elite, via beating the base game or by using a merit?
There could be another solution to get you unstuck there. The DPYes tool has a teleport cheat function, you could try using that to get back to Devils Crossing.