Game crash + save wiped out after adding a minimum release fee

It seems that after editing a save file by adding a minimum release clause to a player game crashes itself.
The error appears during saving the game, after the modification occurred.
I would attach a DMP, but the file is too large, so here's a link:
https://send.vis.ee/download/1666ad628e5a75a0/#Todw3ykO9T7YFR6em2jQ6Q

I was able to pinpoint the issue.
I'll roll out a fix tonight, and introduce a couple of UI features as well.

Status update: Even though I prepared the fix last night, I opted to wait and squeeze in a couple of new features. I should be able to release the update tomorrow.
Besides this bug fix, it's also going to introduce currency selector, extra zoom options for users on larger screens, button to release player on a free, and a dropdown to change player happiness.

v1.6.2 is now available and should fix the issue when adding release clauses to a player's contract. Please grab the latest version and give it a try.