Microsoft, over the weekend, rolled out a fix to address an issue that caused email messages to get stuck on its Exchange Server platforms due to what it blamed on a date validation error at around the turn of the year.
"The problem relates to a date check failure with the change of the new year and it [is] not a failure of the [antivirus] engine itself," the company said in a blog post. "This is not an issue with malware scanning or the malware engine, and it is not a security-related issue. The version checking performed against the signature file is causing the malware engine to crash, resulting in messages being stuck in transport queues."
The Windows maker said the issue impacted on-premises versions of Exchange Server 2016 and Exchange Server 2019 but didn't specify how widespread the impact was.
The issue began to gain attention as the year 2022 kicked in, causing the servers to no longer deliver email messages while throwing the following error message: "The FIP-FS 'Microsoft' Scan Engine failed to load. PID: 23092, Error Code: 0x80004005. Error Description: Can't convert '2201010001' to long."
Microsoft noted that the issue was caused due to a date issue in a signature file used by the malware scanning engine within Exchange Server.
To mitigate the Y2K22 problem, Microsoft is recommending customers to download a PowerShell-based scan engine reset script called "Reset-ScanEngineVersion.ps1" that can then be executed on each Exchange mailbox server used for downloading antimalware updates. It's worth noting that the update will also change the version of the engine to 2112330001.
"The newly updated scanning engine is fully supported by Microsoft," the company outlined. "While we need to work on this sequence longer term, the scanning engine version was not rolled back, rather it was rolled forward into this new sequence. The scanning engine will continue to receive updates in this new sequence."