Well, it looks it was cross-version issue after all.
Logged in Sat and it failed like shown on screenshot. But, I really didn't feel like starting from scratch and just wanted to play. So I copied it to alt, logged her in (it was broken in exact same way), fixed both and played a bit. Noticed how mission journal and exchange window weren't where I like them, fixed those and logged out.
Logged both back in just now and voila, it loaded as it should.
So my guess is that those two changes triggered whole interface to re-write and thus upon save, it was written properly.
In any case, case closed. gg
Logged in Sat and it failed like shown on screenshot. But, I really didn't feel like starting from scratch and just wanted to play. So I copied it to alt, logged her in (it was broken in exact same way), fixed both and played a bit. Noticed how mission journal and exchange window weren't where I like them, fixed those and logged out.
Logged both back in just now and voila, it loaded as it should.
So my guess is that those two changes triggered whole interface to re-write and thus upon save, it was written properly.
In any case, case closed. gg