Partypoker has experienced unexpected downtime on Saturday due to a system upgrade.

An unspecified network error has crashed PartyPokers system a day before the Powerfest kicks off on Feb 21st. According to the company, the system’s downtime was caused by “a routine update to the software deployed earlier this week.” Because of the interruption, Partypoker has chosen to back out from the update until the end of the four-week Powerfest Series.

“We understand the frustration felt by our players who had their tournaments cancelled and rest assured that we will honour all of the guaranteed prize pools in full for those tournaments that started before the technical issues arose last night,” said PartyPoker in a statement. “The customer support team is working around the clock to process these refunds. As you can appreciate this is a substantial task, but should you not receive your refund in the next day or two, please contact customer support who will be happy to assist you further.”

Powerfest series, starting with the Featherweight Week on Sunday, will collectively offer $5 million in guaranteed prizes and runs from Feb 21 through March 20. A total of 98 no-limit Hold’em tournaments will take place at PartyPoker tables