Businesses across the world are grappling with the failure of Microsoft IT systems.
The infamous blue loading screen on Windows PCs is being displayed at retail checkouts, from cafés to department stores.
Microsoft says the "underlying cause" of the mass IT outage has been fixed for its apps, but "residual impact" is continuing to affect some services.
It previously stated it was "investigating an issue affecting Windows devices due to an update from a third-party software platform."
This platform is confirmed as IT security firm CrowdStrike, which is also monitoring the failure of its technology connected to Microsoft.
Airports have been hit hardest, with planes grounded and passengers left stranded across the globe.
At Stansted Airport in London, UK, a spokesperson told the BBC that “some retail payment machine services have been impacted". At Gatwick Airport, coffee chain Starbucks is reportedly only accepting cash.
UK bakery and coffee shop chain Gail's is experiencing similar problems with signs stating it cannot take in-store payments and apologising for the inconvenience to customers.
UK grocery retailer Morrisons said it had "some issues" with payment in some stores but these have now been resolved. Other UK retailers reported spikes in tech issues, including Tesco and Sainsbury's, but this has begun to calm.
Parcelhero, a UK delivery service, said the crowdstrike outage could cause "significant global supply chain problems".
David Jinks, Parcelhero’s head of consumer research, added: "Many airports, ports, railways and retailers reported problems as a result of the IT outage.
"Delayed flights and issues with IT systems at airports will impact airfreight. Not only will slots for dedicated airfreight flights be disrupted but many international goods and packages are transported not only in specially designed cargo planes but also in the cargo holds of passenger aircraft. One thousand flights globally were reported to have been cancelled by Friday mid-morning.
"International ports have also been impacted by the issues. For example, Poland’s largest container terminal, the Baltic Hub in Gdansk, asked companies to stop sending containers to the port."
Retail’s reliance on Microsoft
Just Food sister site Retail Insight Network recently analysed the role of Microsoft in the retail industry, highlighting its omnipresent influence across retailers’ operations and its global network of 135m managed devices.
The current outage highlights the risks of businesses using a single provider for IT systems, particularly for POS (point-of-sale) systems.
GlobalData’s retail intelligence finds that growth in the POS software market is driven by the increasing adoption of cloud-based solutions and escalating demand for contactless payment methods - precisely the technologies that the current global outage has impacted.
While current evidence suggests that this outage is a system failure rather than a cyberattack, the importance of cybersecurity for retailers remains paramount in an age where technological issues can bring the retail industry to a standstill.