Shopify was hit by a major technical outage on Cyber Monday (1 December), blocking access to the management interfaces of thousands of ecommerce sites across the UK, US and Europe.

According to Reuters, the incident chiefly affected American users, but European merchants were also impacted. A peak of 2,500 crash reports in the UK was recorded at around 2:45pm GMT.

A report in Fashion Network cited stats from Downdetector which recorded malfunctions hitting a peak at 4pm GMT, when over 4,000 crash notifications were reported simultaneously. 2,400 users still reporting access problems at 5:37pm GMT.

In an update issued as the outage continued, Shopify urged business owners to remain logged in on any devices and to avoid logging out as they may not be able to log back in.

Reports indicate the outage extended beyond back-end access issues with physical retailers also hit and unable to process payments through Shopify-powered POS systems – halting in-store transactions across parts of the network.

“We have identified and corrected an issue in our connection authentication flow, and we are now seeing signs that administrator and POS connections are being re-established,” stated Shopify on Monday.