Microsoft issues a fix for Exchange Y2K22 bug that shut down company emails

Illustration by Alex Castro / The Verge

If you woke up on January 1st, 2022, and found that your work email’s inbox was unusually empty, you aren’t alone. Microsoft rang in the New Year with a bug that prevents Exchange servers from sending emails, but fortunately, a fix has since been issued, as detailed in a report by Bleeping Computer.

“The problem relates to a date check failure with the change of the new year and is not a failure of the AV engine itself,” Microsoft explains in a post on its Tech Community forum. “The version checking performed against the signature file is causing the malware engine to crash, resulting in messages being stuck in transport queues.”

Microsoft outlines the solution to the problem in its post, requiring administrators to either implement the fix manually or apply an automated script. The post also contains a detailed FAQ, noting that the solution “will take some time” for administrators to implement. And depending on how many emails are stuck in the queue, it may take a while for the messages to land in their intended recipients’ inboxes.

Problems started cropping up at midnight on January 1st, with an Exchange administrator on Reddit calling attention to the issue. As explained by Bleeping Computer, administrators began noticing error messages in the Exchange Server’s Event Log, such as “The FIP-FS Scan Process failed initialization. Error: 0x8004005. Error Details: Unspecified Error” or “Error Code: 0x80004005. Error Description: Can’t convert “2201010001” to long.”

Administrators were forced to come up with alternate solutions during the time it took for Microsoft to address the issue, but now that the company has released an official fix, it looks like the Y2K22 crisis is over.