When you try to sign in to Copilot in Microsoft 365, you may see error AADSTS50105. This error means the user account is not assigned to the required license or application role. The error prevents access to Copilot features in apps like Word, Excel, and Teams. This article explains the root cause and provides step-by-step … Read more
When you upload a file to Copilot in Microsoft 365, you may see an HTTP 413 error that stops the process. This error means the server rejected the file because its size exceeds a defined limit. The root cause is typically a restriction in the Microsoft 365 tenant configuration or a local proxy setting that … Read more
When you open the Microsoft 365 admin center to configure Copilot, you may see a red error banner that reads “Service Principal Not Found.” This error prevents you from enabling Copilot features or managing data source permissions for your tenant. The root cause is a missing or misconfigured service principal object in Microsoft Entra ID, … Read more
You open PowerPoint to use Copilot for creating slides, but the Copilot pane shows a spinning wheel and the message “Initializing” that never goes away. This usually happens because the Copilot service is waiting for a required dependency such as network authentication, a Microsoft 365 license check, or a local cache file that has become … Read more
When you try to sign in to Copilot in Microsoft 365, you may see the error message AADSTS50158 External Security Challenge. This error means that Azure Active Directory could not complete an external authentication challenge that your tenant requires. This is not a Copilot bug. It is a conditional access policy or identity protection rule … Read more
You reset your Microsoft 365 password, and now Copilot shows an “Invalid Grant” error when you try to use it. This error appears in the Copilot pane, in Microsoft Teams, or in the Copilot mobile app. The problem occurs because your cached authentication token is no longer valid after the password change. This article explains … Read more
When you connect to your corporate VPN and try to use Copilot in Microsoft 365, you may see a red error banner that says “Network Unreachable.” This happens because Copilot requires direct HTTPS access to specific Microsoft endpoints, and many corporate VPNs route traffic through restrictive proxies or block certain domains. The error can appear … Read more
When you launch Copilot on Windows 11, you may see an error message about the Web Account Manager Broker. This error prevents Copilot from signing in or responding to your queries. The root cause is a corrupted or misconfigured WAM component that handles authentication between Windows and Microsoft services. This article explains why the WAM … Read more
If you see a “TLS Handshake Failed” error when trying to use Copilot in Microsoft 365 apps on an older Windows client, your connection is being blocked before Copilot can respond. This error means the secure communication channel between your device and Microsoft servers could not be established. The root cause is almost always an … Read more
When you use Copilot in Microsoft 365, you may see the error AADSTS9002313 with the message Invalid Request. This error stops Copilot from generating responses, drafting documents, or accessing your data. The cause is almost always a malformed authentication token or a mismatch in the token request parameters sent by the client app to Azure … Read more