Morroblivion v0.64 - Every time, with every door, I get a CTD when I try to enter the Balmora Mage's Guild. It happens after the loading screen finishes. After some experiments I determined that if I unload the Morrowind_ob - Lost Magic OBME.esp I can enter no problem. Apparently this doesn't happen every time as in a previous game with this esp loaded I could enter said guild.
You can post about mod issues
You can post about mod issues in the mod's thread, no need to create a new one for that.
Regarding the issue itself, I'm afraid I can't help you much. Someone reported the same a long time ago, but I can't fix something that I can't reproduce in my game.
You can try doing a "clean save", i.e deactivate Lost Magic esp, go into the game and save without it, then activate esp again.