KFC was forced to temporarily close nearly all of its Britain locations February 19 as it faced supply issues stemming from a recent partner change. According to CNN, about 800 of the YUM! Brands’ chain’s 900 or so locations in Britain were closed as of midday on Monday, with some opening for business by the afternoon.

On its website, KFC said: “We’ve brought a new delivery partner onboard, but they’ve had a couple of teething problems—getting fresh chicken out to 900 restaurants across the country is pretty complex.”

KFC made a supplier change from South African-owned Bidvest Logistics to DHL on February 14.

“We won’t compromise on quality, so no deliveries has meant some of our restaurants are closed, and others are operating a limited menu, or shortened hours,” KFC added.

DHL credited the delays to “operational issues.”

“We are working with KFC and our partners to rectify the situation as a priority and apologize for any inconvenience this may have caused,” a spokeswoman told Reuters. DHL said a number of its deliveries were “incomplete or delayed,” according to CNN, and was working with KFC to remedy the issue.

The vast majority of KFC’s restaurants in the U.K. are franchised. KFC said in a statement it would pay its staff as normal and asked franchisees to follow suit. The chain said company-operated restaurants would pay staff on short-term contracts the average hours worked per day over the past 12 weeks. Salaried members would be paid as normal.

U.K. system sales were up 2 percent in the fourth quarter versus the prior-year period for KFC, and 5 percent for the fiscal 2017.