This week, network and IT administrators reported that some end users were unable to use Microsoft Outlook or other Microsoft 365 applications.
On Monday, numerous administrators contacted BleepingComputer to report that some of their users were experiencing disruptive issues with Microsoft Outlook. These issues included the program not opening, freezing after opening, mail delivery delays, and errors stating that the user did not have a valid license.
These equivalent issues were affirmed by other administrators on Reddit [1, 2, 3] and in the Microsoft discussions.
“Does anyone have any issues with the office? A Reddit post states, “We have a department that is using an HP Probook 450 G9, and every single one of them is experiencing Outlook, Word, etc. being extremely slow and not responding.”
“A lot of users in my organization are reporting that they are unable to sign in to Teams or Outlook, but the status page does not list these symptoms. They appear to be able to enter by switching their licenses from business basic to e1. Anybody heard anything?,” Reads another Reddit post.
“Some users are unable to sign in and authenticate using desktop applications. Even the Defender scan when installing new software reports that it is unable to connect to some Microsoft connection. The weather widget is unavailable. Word, Teams, and OneDrive are all down. However, they can utilize browser versions,” a different administrator observed.
BleepingComputer has seen the majority of complaints about Microsoft Outlook, but users have also reported experiencing crashes and freezes in Word, Excel, and Teams.
Despite the fact that Microsoft has not made any public disclosures regarding these issues and has yet to respond to BleepingComputer’s request for additional information, a number of network administrators have devised a variety of solutions that assisted in resolving the issues on their network.
The workarounds shared by various admins in the Reddit threads above include:
- Ensure the Outlook, SharePoint, or other Microsoft 365 apps are enabled for users in the Azure AD Tenant.
- Remove and add back Microsoft 365 licenses to impacted users.
- Disable the Internet Protocol Version 6 (TCP/IPv6) setting in the workstation’s network adapter properties.
- Uninstall EDR security software seemed to help with performance (Not recommended as a solution).
However, not all of these solutions have been successful.
“There are no Mac reports at this time, but the Windows reports keep coming in. Based on the other comments, I tried removing and adding users’ A3 licenses in Azure AD, but that had no effect,” a administrator shared this today.
Until these issues are resolved, some administrators have switched affected users to Outlook on the Web (OWA).
This issue is so frustrating because it does not affect all tenants or even all tenants’ users, making it difficult to determine what is causing it.
Microsoft released a workaround on Tuesday for a bug in Microsoft Outlook that also causes performance issues and freezes when the application is launched.
“One known reason for this side effect is store re-preparing. Microsoft states, “This is anticipated if the user has created a new profile or manually switched from REST to MAPI by deactivating Shared Calendar Improvements.”
“However, running such applications can force this toggle unexpectedly due to endemic problems in the reading service enabled feature’s status.”
However, as there is no mention of missing licenses or issues with other Microsoft 365 apps, it is unclear whether this is the same issue administrators have reported or something else.
Microsoft has been contacted once more by BleepingComputer to determine whether they are aware of the issue and whether there are any workarounds. However, a response was not immediately available.