• Description:
   I don't know it happened but i suddenly have -144k golds per turn when i was building 31k+...
  The totals of army upkeep changed from -1853 per turn to -82424 per turn!
  Money from alliance changed from +758 to -3270
  Number of Territories in your sphere of influence from +16975 to -73898 ..... xD
  For no reason the amount of Money changed so much it is impossible to sustain.
  If you continue anyway, you can accumulate as much debt as you want without bankkrout.
  
  
• Attachments:
    auto-save 890.ctr and auto-save 891.ctr
  
  
  
• Steps to Reproduce:
  1. pass everything to turn 461 // 2. check the Money account 
  
  
• Expected Behavior:
  The total must not change like that there is no reason i loose -200k per turn doing nothing. 
  
  
  I hope all of this is precise enought for you to fix it.
  You have the saves attached do not hesitate to contact me for further information.
  
  Best regards,
  
  Siamon

I get the same behavior. it looks to me to be a Integer Overflow of some type.

I'm also on PC/Win10/Steam same build version as OP.

Here's my screenshot and save game.

Chinese Turn 281.ctrChinese Turn 282.ctr