A critical bug in Microsoft Outlook has been fixed, but not before it caused widespread disruption for users of the Copilot Chat feature. The issue, which was reported to have affected users with the Copilot Chat (Basic) license, saw the Copilot buttons disappear from Classic Outlook on Windows devices. This meant that users were unable to access key features and functionality through the traditional interface.
The problem manifested in several ways, including the complete disappearance of the Copilot button from the top-right area above the ribbon, as well as its absence from the left app bar or More Apps area. Even when attempting to add Copilot through ribbon customization, users encountered issues with the command being unavailable or grayed out. However, it’s worth noting that those affected could still access Copilot through other entry points, such as Outlook on the web or the Microsoft 365 Copilot standalone app.
Microsoft acknowledged the issue and took swift action to address it, implementing a service change on June 29th. The company advised users who were still experiencing problems to restart their email client, which would trigger the fix immediately. Additionally, those with access to updates were recommended to apply the latest build by selecting File > Office Account > Update Options > Update Now.
Interestingly, this isn’t an isolated incident for Microsoft Outlook users. In recent months, the company has been working to resolve a number of known issues that have affected Classic Outlook performance and functionality. For example, in March, Microsoft addressed problems with sending emails via Outlook.com, while also fixing an issue that rendered the client unusable for those who enabled the Microsoft Teams Meeting Add-in.
While these fixes are welcome news for users, they do highlight the importance of regular updates and maintenance to ensure that software remains secure and functional. As cybersecurity experts know all too well, even seemingly minor issues can have significant consequences if left unaddressed.
For those affected by this latest bug, it’s worth taking a step back to review their email client settings and ensure that they’re running the latest version of Outlook. This simple precaution can help prevent similar problems in the future. As we continue to navigate an increasingly complex digital landscape, staying ahead of potential issues is crucial – and Microsoft’s swift response to this bug serves as a reminder of the importance of proactive software maintenance.
Source: Bleeping Computer — 2026-07-02