Yep, was random after all.
God bless devs, for implemented "each end-of-turn autosave" (MoM had it like every 3 or 5 turns... which had to to play through several turns before I got where the game dropped me out)

It was spell Aether Binding, but obviously, as you said, it was actually random, as ...

Hi,

not only I am not certain, that this is the right place to report bugs (as I bought CoM on GoG), but I do not even have detailed report of the problem.
Basically game froze during AI move, when Jafar tried to cast a spell.
Should be low-tier spell, as not only the game did not progress (time ...