I created more than 100 alternatives for one model to be calculated. The simulation succeeded.
Since I did not find appropriate measure, I had to change the model slightly and I had to repeat the calculation for the same amount of alternatives. Instead of repeating the procedure for the original model, of course I tried to Save project As...
After I changed the seed model to the updated one (not just in PAT GUI; I had to delete the original one in explorer too) I ran the new set of alternatives. Failure... :(
Can anyone advise? Thanks!