It's the latest issue for those receiving unemployment in New Jersey — some folks saw double payments of the federal $300 supplement in a week, while other were skipped entirely as a result of a computer system upgrade, according to state officials.

The state's unemployment insurance system, which operates using a decades-old programming language, has been beset with problems since the start of the pandemic.

Get our free mobile app

The spike of thousands signing up to receive benefits bogged down the "legacy" system and caused substantial delays in processing some payments.

Some good news, according to state Office of Information Technology and Department of Labor officials, is that migrating the mainframe processing to a new, much faster platform over the weekend will "significantly enhance online service delivery" to all claimants as well as anyone using other online state systems.

In the short term, the work could cause a delay in receiving the $300 unemployment supplement, as payments usually processed early in the weekend were delayed. Claimants unable to certify this past Sunday will have to wait until Friday so they don't miss a week of benefits.

In contrast, a "small group" of claimants received more than one $300 payment for the week of June 5.

"To satisfy the overpayment, no $300 payments were issued to this group of claimants for the week ending June 12. Those who received more than one extra $300 payment will see their $300 payments continue to be offset until the overpayment is satisfied. Any claimant who was not overpaid previously but received no FPUC payment this week will receive two FPUC payments ($600) on June 21-22," a spokesperson wrote to New Jersey 101.5.

COVID relief for NJ municipalities: How much is your town getting?

The American Rescue Plan signed by President Joseph Biden awards $10.2 billion to New Jersey. Here is a a county-by-county and town-by-town breakdown.