I have triple tested that the same campaign folder works fine in 1.1 but it gives error in 1.2.
After some research (thanks to -show_err) I have seen that all the problems come from the position of the ports. The game can rid on the position of the ports in map_regions, but if there is a port built in descr_strat the game crashes (return to the campaign selection menu).

From these results it seems that 1.2 is more exigent with the position of the coast line and the different maps (map_regions, map_ground_types...) must fit much better than in 1.1.
I will try to modify the position of the ports and I will post the final result.

Cheers.