Oops.

A computer error has Milwaukee County, Wisconsin , facing a $4.56 million hole in its proposed 2027 budget .

The problem came to light Wednesday, just one day after County Executive David Crowley defeated Republican Tom Tiffany in Wisconsin's gubernatorial race. The Milwaukee County Board of Supervisors is set to vote on that budget Thursday.

The shortfall stems from a switch to an automated system for handling some budget calculations that were previously done by hand. A mistake in the system's formula reversed the positive and negative signs on two financial entries involving the county airport, throwing off its budget projections.

The error affected two accounts tied to Milwaukee County's airport budget. The system incorrectly calculated a $4.49 million airport depreciation contribution and about $2.21 million in airport revenue from reserves, making it appear the county would save $4.6 million more in property taxes than it actually would, according to WISN .…