For thousands of IT managers, the return to work after the new year began with a communications crisis. Classic Outlook users who upgraded to 19426.20218 in the Current Channel lost the ability to read encrypted messages. Instead of the email content, the system displays a credential verification error message and an unreadable `message_v2.rpmsg` attachment. Microsoft confirmed the problem on 6 January by launching an investigation, but at the time of this writing, an official patch had not been released.
The situation is serious because it affects the business-critical Information Rights Management (IRM) mechanism. The bug technically lies in a regression in the way the mail client processes RPMSG containers when attempting to retrieve usage licences. As a result, secure mail becomes a digital deadlock. Microsoft is now suggesting ad hoc solutions, including forcing senders to change their encryption method (via the ‘Options’ ribbon instead of the ‘File’ menu) or the complicated for the average user process of rolling back the Office version to compile 19426.20186 via the command line.
This failure is part of a worrying trend observed in recent quarters. Although Microsoft officially guarantees support for classic Outlook until at least 2029, the stability of this platform is becoming a matter of debate. This is the third major incident in the last four months – following November’s Exchange Online connectivity issues and October’s disappearance of the application from Windows systems.
For IT decision-makers, this is a wake-up call. The Redmond giant is aggressively promoting the ‘New Outlook’, a web-based application that continues to attract resistance in corporate environments due to functional shortcomings and data privacy concerns. The increasing frequency of bugs in the classic version can be interpreted in two ways: as a result of the technological debt of the old code or, as more cynical market observers suggest, a form of ‘soft extinguishing’ the product by lowering the priority of quality control. Regardless of Microsoft’s intentions, companies relying on the classic Exchange architecture need to prepare themselves for the fact that using it will require increasingly frequent administrative interventions.
