If you often work with several Microsoft Office apps open at the same time, you may have noticed that Copilot doesn't always respond properly. Microsoft has confirmed that it’s investigating a bug affecting Microsoft 365 users when multiple Office desktop applications are run simultaneously on the same system.
The problem arises when one app (like Excel) initiates a WebView2 instance—used to power web-based features within Office apps—and another app (such as Word) attempts to start its own instance concurrently.
The result: the Copilot panel fails to open, and in some cases, other WebView2-dependent features like Share or Room Finder also malfunction.
According to Microsoft’s support documentation, the issue affects Microsoft 365 desktop clients, particularly:
The bug occurs regardless of the operating system, meaning it can affect both Windows 10 and Windows 11 systems.
If the app that initially launched WebView2 is closed, the issue typically resolves temporarily, allowing Copilot to function again in other apps.
Copilot error (Source: Microsoft)
In an official statement, Microsoft confirmed:
“Several customers have reported issues with Office features that depend on WebView2, mainly Copilot, Share, and Room Finder. The most noticeable symptom is the Copilot pane failing to load when multiple Office apps are running concurrently.”
Microsoft’s Office team is working on a permanent fix and will share more details as soon as a patch or update becomes available. Until then, they recommend avoiding the simultaneous use of multiple Office apps, especially those using Copilot.
The bug stems from how Office handles WebView2 instances—a core component that integrates modern web capabilities into local apps.
When an Office app like Excel is launched, it initializes its own WebView2 instance to run modern features like Copilot, Smart Lookup, or interactive components.
A conflict arises when a second app tries to create a new instance while the first is still active, causing an initialization error that blocks Copilot from launching.
In simple terms: Office apps are competing for the same resource, and that conflict causes Copilot to crash or remain unresponsive.
Read more: Microsoft 365 Copilot: New Design and New Features
This isn’t the only issue Microsoft has tackled recently. Other critical Microsoft 365 bugs include:
These incidents show that while AI tools like Copilot boost productivity, they also introduce technical complexity that can impact user experience.
If you're experiencing Copilot issues in Office apps, here are signs that you may be affected:
These symptoms typically indicate a WebView2 instance conflict.
Learn more: How does Microsoft Copilot work in Azure?
Until Microsoft issues an official fix, here’s what you can do:
This issue highlights that AI and productivity integration is still maturing.
Copilot relies on many layers—AI, cloud services, WebView2, and Office infrastructure—so even small incompatibilities can significantly impact usability.
For organizations, it’s essential to test AI tools in controlled environments before large-scale rollouts. At TecnetOne, we recommend progressive pilots, close monitoring, and documentation of issues to improve IT support and responsiveness.
Microsoft is actively investigating the Copilot bug caused by simultaneous Office app usage. While it doesn't pose a security threat, it can hinder productivity for users who rely on Copilot for daily tasks.
Until an official fix is released:
At TecnetOne, we stay ahead of incidents like this to help you maintain a stable, productive, and secure digital workspace. When your tools fail, knowing how to respond quickly is the key to staying on track.