THE CRUNCH
A recent Edge update has left some New Outlook users unable to open email attachments. Microsoft says Edge 156 "unintentionally enabled an unnecessary configuration", which removes the Open option for attachments and, for some users, produces an error saying the file cannot be opened along with an instruction to restart Outlook. After the error appears, the Open option disappears entirely. The company confirmed the issue in advisory EX1528992 and began rolling out a fix that disables the configuration. It expects the rollout to take around 12 hours, after which users will need to close and reopen New Outlook.
In the meantime, there is a workaround: use Save As to save the attachment, then open the file manually. Classic Outlook does not appear to be affected, according to Microsoft's advisory for Exchange Online, so the glitch briefly adds opening attachments to the list of things the old client can do that the new one cannot.
The episode is a reminder of how tightly Microsoft's software is woven together. An unexpected change in Edge might reasonably be expected to cause rendering oddities in New Outlook, but losing the ability to open attachments because of a browser update may prompt administrators to think harder about the blast radius of software updates. The Register has asked Microsoft for more detail on the configuration involved.