Microsoft 365

Title: Users are unable to access archived email messages in Outlook on the web User impact: Users are unable to access archived email messages in Outlook on the web. More info: When users try to access archived email messages in Outlook on the web, they may see the error message “Your message cannot be displayed right now.” Current status: We're reviewing HTTP Archive format (HAR) network trace logs to help identify the root cause of the event, so we can determine our next troubleshooting steps. Scope of impact: Your organization is affected by this event, and some users attempting to access archived email messages in Outlook on the web are impacted. This section may be updated as our investigation continues. Next update by: Tuesday, March 24, 2026, at 1:00 PM UTC

Title: Investigating user reports of Microsoft 365 Admin Center issues in the United States User impact: We don't have details on impact yet. We're seeing an increase in user reported issues above our alerting threshold. Current status: We are reviewing service telemetry and available information to determine if there is an issue happening and we'll update this message shortly with our latest findings. This communication serves as a preliminary notification about a potential issue affecting your service.

Title: Some users may be unable to access the Microsoft 365 web sign-in page and the Microsoft 365 Copilot web sign‑in page User impact: Users may be unable to access the Microsoft 365 web sign-in page and the Microsoft 365 Copilot web sign‑in page. More info: Users can access Microsoft Copilot through application-based Microsoft Copilot services. This includes, but is not limited to: - Microsoft Copilot desktop app - Copilot in Microsoft Teams - Copilot in Office apps User may be able to leverage https://m365.cloud.microsoft/search, and should be able to sign in using this page. Once signed in, users can access Office.com. Current status: We've identified that a section of service infrastructure is not processing traffic efficiently. We're making configuration changes to remediate impact. Scope of impact: Impact is specific to some users who are served through the affected infrastructure. Root cause: The infrastructure that supports access to the Microsoft 365 web sign-in page and the Microsoft 365 Copilot web sign-in page is not processing traffic efficiently, preventing some users from accessing the service pages. Next update by: Friday, April 3, 2026, at 12:30 AM UTC

Title: Users may be unable to access or have delays accessing the Microsoft 365 admin center User impact: Users may be unable to access or have delays accessing the Microsoft 365 admin center Current status: We're investigating reports of an issue in which users may be unable to access or have delays accessing the Microsoft 365 admin center. We are reviewing service telemetry and available information to determine if there is an issue happening and we'll update this message shortly with our latest findings. Scope of impact: Any users attempting to access the Microsoft 365 admin center may be impacted. Next update by: Thursday, April 2, 2025, at 9:00 PM UTC

Users report Microsoft Outlook and Excel crashing, login issues, and data fetching problems in Office 365 starting from 4-1-26.

Title: Users may be intermittently unable to access their Exchange Online mailboxes in some connection methods User impact: Users may be intermittently unable to access their Exchange Online mailboxes in some connection methods. More info: This issue may intermittently impact some users who attempted to access the Exchange Online service through the Outlook mobile apps or the new Outlook for Mac desktop client. Current status: We've received reports from affected tenants that the impact scenario originally communicated through SHD EX1256020 is still ongoing. We're working to restart the Notification Broker service on affected portions of Exchange Online service infrastructure to remediate impact while we continue our analysis into the underlying root cause. Scope of impact: Impact may occur intermittently for some users accessing their Exchange Online mailboxes in the Outlook mobile apps or the new Outlook for Mac desktop client. This section may be updated as our investigation progresses. Next update by: Thursday, April 2, 2026, at 11:30 PM UTC

Title: We're looking into a potential problem impacting Microsoft 365 Copilot Chat User impact: We're checking for potential impact to your users. Current status: We're investigating a potential issue impacting Microsoft 365 Copilot Chat and checking for impact to your organization. We'll provide an update within 30 minutes.

Title: Users are unable to access archived email messages in Outlook on the web User impact: Users are unable to access archived email messages in Outlook on the web. More info: When users try to access archived email messages in Outlook on the web, they may see the error message “Your message cannot be displayed right now.” Current status: We're reviewing HTTP Archive format (HAR) network trace logs to help identify the root cause of the event, so we can determine our next troubleshooting steps. Scope of impact: Your organization is affected by this event, and some users attempting to access archived email messages in Outlook on the web are impacted. This section may be updated as our investigation continues. Next update by: Tuesday, March 24, 2026, at 1:00 PM UTC

Title: Some users experience errors when attempting to create shared mailboxes in Exchange Online User impact: Users experience errors when attempting to create shared mailboxes in Exchange Online. As a workaround users are able to create a user mailbox and convert it to a shared mailbox. Current status: We're analyzing support provided information to determine our next troubleshooting steps. Scope of impact: Your organization is affected by this event, and some users attempting to create shared mailboxes in Exchange Online may be impacted. Next update by: Friday, March 20, 2025, at 1:30 PM UTC

Title: Investigating user reports of issues with Microsoft 365 products User impact: We don't have details on impact yet. We're seeing an increase in user reported issues above our alerting threshold. Current status: We are reviewing service telemetry and available information to determine if there is an issue happening and we'll update this message shortly with our latest findings. This communication serves as a preliminary notification about a potential issue affecting your service.

Title: Some users may be unable to access Office.com or the Microsoft 365 Copilot web sign‑in page User impact: Users may be unable to access Office.com or the Microsoft 365 Copilot web sign‑in page. More info: The impacted web-client is office.com, and impacted Microsoft 365 Copilot web-clients are office.com/chat, m365.cloud.microsoft, m365.cloud.microsoft/chat and copilot.cloud.microsoft. Users can access Microsoft Copilot through application-based Microsoft Copilot services. This includes, but is not limited to: - Microsoft Copilot desktop app - Copilot in Microsoft Teams - Copilot in Office apps User may be able to leverage https://m365.cloud.microsoft/search, and should be able to sign in using this page. Once signed in, users can access the impacted web-based office.com and Copilot clients. Current status: We've identified that impact associated with MO1253428 has started to reoccur. We're reviewing traffic pattern telemetry and applying configuration changes to optimize connections and remediate impact. Scope of impact: Impact is specific to some users who are served through the affected infrastructure. Next update by: Tuesday, March 17, 2026, at 4:00 PM UTC

Title: Some users may be unable to access Office.com or the Microsoft 365 Copilot web sign‑in page User impact: Users may be unable to access Office.com or the Microsoft 365 Copilot web sign‑in page. More info: The impacted web-client is office.com, and impacted Microsoft 365 Copilot web-clients are office.com/chat, m365.cloud.microsoft, m365.cloud.microsoft/chat and copilot.cloud.microsoft. Users can access Microsoft Copilot through application-based Microsoft Copilot services. This includes, but is not limited to: - Microsoft Copilot desktop app - Copilot in Microsoft Teams - Copilot in Office apps Current status: We've identified that a section of service infrastructure is not processing traffic efficiently. We're making configuration changes to remediate impact. Scope of impact: Impact is specific to some users who are served through the affected infrastructure. Next update by: Monday, March 16, 2026, at 4:30 PM UTC

Title: Potential issues accessing mailboxes via one or more connection methods User impact: Users may experience errors or failures when accessing their mailbox via one or more Exchange Online connection methods. Current status: We're investigating a potential issue and checking for impact to your organization. We'll provide an update within 60 minutes.

Title: Users may be unable to save their personalization settings within Microsoft Copilot Chat and encounter an error User impact: Users may be unable to save their personalization settings within Microsoft Copilot Chat and encounter an error. More info: Affected users may see a "Something went wrong, and we couldn't save your changes. Try refreshing the page." banner. Current status: We're investigating a potential issue with Microsoft Copilot Chat and checking for impact to your organization. We'll provide an update within 30 minutes.

Title: Some users may be unable to use classic Outlook when the Teams Meeting Add-in is enabled User impact: Users may be unable to use classic Outlook when the Teams Meeting Add-in is enabled. More info: Specifically, impacted users may experience crashes while using the classic Outlook on any client, or be unable to launch the service. While we work on the permanent fix, we recommend impacted users upgrade to the latest Outlook version. As a workaround, users can also perform an Online Repair of Office or update Outlook to the latest version to resolve the issue. Current status: We're analyzing support provided information to determine our next troubleshooting steps. Scope of impact: Some users that are attempting to use classic Outlook with the Microsoft Teams Meeting Add-in version 26043.2016.4478.2773 enabled may be impacted. This information may be updated as our investigation continues. Next update by: Tuesday, March 17, 2026, at 9:00 AM UTC

Title: Some users may be intermittently unable to access their Exchange Online mailboxes with the Outlook mobile apps User impact: Users may be intermittently unable to access their Exchange Online mailboxes with the Outlook mobile apps. More info: This issue impacts both the Android and iOS mobile app experiences. Current status: We're analyzing Outlook mobile logs to isolate the root cause of impact and establish a fix. Scope of impact: Impact may occur for some users intermittently unable to access their Exchange Online mailboxes with the Outlook mobile apps. Next update by: Thursday, March 19, 2026, at 4:30 PM UTC