I tested Questdog's savegame, and it still had a WfOC error with an infinite loop in the Italian Player's turn.
I'm on it too, and I think the problem is after Italian Player's turn.
The loop you mention in the Italian Player turn seems to be the same as in Joseph'savegame :
when IA has to choose a Tech, it use the CvPlayerAI::AI_bestTech(), that use CvPlayerAI::findBestPath() method.
If I understand right, the IA try to find the better way in the Tech tree. And for that, it evaluate each Tech, depending of which building is able to be build in all the city the AI has.
here the whole call tree
it's not a closed loop, but as it performs the evaluation for each tech, it takes time.
In my case, it has been resolved after 73 loops, with choosing Tech 'Domestication des Mastodontes' sorry I'm using French text. (line 16317 in the debug output)
After that, the other AI are calculating, until the player 50 (I presume its barbarians).
After a lot of 'AI_Update for unit' that seems to make sense, it has an endless loop on 3 Units ??
I Tried to bypass the loop (it's in CvGame::update(), line 2765), but after endind the method, the exe take the hand back (machine code), and execute the CvGame::update() again.
Results : it's a closed loop. There is perhaps a way to workaround that by deleting in the Worldbuilder the three units that are causing trouble.
Does someone knows how to find a unit by its number (5171722 for example) ?
Edit : I think I've found : the units are on plot 154,116, two of Type AI_COUNTER, and one of Type AI_ATTACK_CITY
I don't have enough experience for now in AI behavior to solve that, but what I understood is 1 Unit wants to make a Group to Attack, and the Two others always break the group.