New game, something broke badly.
Everything was going fine until the Khmer apparently found the monolith. Two turns later - they founded about 10 religions, built two dozen or so world wonders, and skipped two eras into the future in tech.
Peeked into their capital and realized what went wrong - see attached screenshot.
Added a zipped save game too if needed.
Edit: Added savegame from the turn before the numbers go crazy in his capital, might be more helpful for figuring this out
Everything was going fine until the Khmer apparently found the monolith. Two turns later - they founded about 10 religions, built two dozen or so world wonders, and skipped two eras into the future in tech.
Peeked into their capital and realized what went wrong - see attached screenshot.
Added a zipped save game too if needed.

Edit: Added savegame from the turn before the numbers go crazy in his capital, might be more helpful for figuring this out