re: South Carolina has $1.8B but doesn't know where the money came from or where it should go

While 1.8B extra is certainly better than being 1.8B short, this is still a significant problem.;

They have no idea from where this came, how long it's been building up, etc.

By any chance, I wonder if this doesn't in some way related to unclaimed property. Maybe there's a second account that unclaimed proeprty was being put in, and the records are so bad that no one realized it?