COOK COUNTY, Ill. (WLS) — The I-Team has discovered significant county-wide delays affecting individuals awaiting property tax refund checks. These issues stem from complications arising during a technology upgrade.

The Cook County treasurer says the delays are also stopping revenue from going to municipalities.

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The I-Team is finding that millions of dollars are sitting in limbo at the Cook County Treasurer’s Office.

The treasurer is blaming the technology company hired to upgrade the county’s computer systems.

Cook County computer systems from the treasurer, clerk and assessor are being combined into a single system.

The county has paid Tyler Technologies close to $29 million, but, about 10 years into the contract, there are delays.

The I-Team acquired a letter dated July 10 through a Freedom of Information Act request, authored by Treasurer Maria Pappas to Cook County President Toni Preckwinkle.

In this letter, Pappas mentions that setbacks caused by a private computer company are obstructing $216 million in property tax payments to 2,200 taxing bodies depending on this revenue. Additionally, the treasurer’s office is unable to issue $56 million in refund checks due to 25,000 property owners.

Preckwinkle responded in a letter, saying the treasurer’s office was not taking the proper action to prepare. But the treasurer denies that allegation, saying her office says it has been working around the clock.

And there are more delays when it comes to making assessment corrections.

The Cook County Assessor’s Office said that “…due to a countywide technology upgrade, the processing of Certificates of Error is temporarily on hold. This means that approved applications will not be issued refunds until the upgrade is complete… .”

“We empathize with homeowners; we understand it can be a frustrating process, and we are doing everything in our power to smooth this out,” said Angelina Romero, chief communications officer with the Cook County Assessor’s Office.

Tyler Technologies issued a statement to the I-Team, saying: “We continue to fully support Cook County as they move forward with their data review and full system implementation.”

Tyler added it’s been ensuring that data information being converted has been accurate, and that additional data resulted in changes.

In another letter, Cook County Treasurer Maria Pappas wrote to Tyler Technologies in May, saying: “Time and time again, Tyler has missed deadlines through the course of this project… Until resolved, we remain in limbo.”

Tyler Technologies responded to Pappas, saying: “While your letters tempt us to offer additional responses, we are laser-focused on the successful go-live we have worked hard to accomplish.”

County leaders say the computer issues will also delay the second installment of Cook County tax bills, which are usually due Aug. 1.

Once the upgrades are complete, the county says they will improve the processing of certificates of errors and refund checks.