Heroes of Might and Magic III - Complete Collection + Era2 + VCMI + Utility.

I mainly choose mods in the VCMI window.
The following mods are installed:

I understand that you are playing the VCMI version. These heroes have been in development for a long time, but its version hasn't even reached version 1.0 (the current version is 0.99), so there may still be many bugs and shortcomings (although a lot of content has already been modded for VCMI). I added it to my VCMI build relatively recently, based on the principle of "why not?". Most likely, many errors will be fixed in the near future.

P.S. Are crashes with portals also occurring if you play the original VCMI without any connected mods?!