Loading story…
Microsoft reverted a service update after it caused some Microsoft Teams desktop client users to become stuck on the loading screen with the error, “We’re having trouble loading your message. Try refreshing.” The company tracked the disruption as incident TM1283300, initially describing it as a transient service infrastructure issue before identifying the root cause as a regression in the Teams client build-caching system that pushed some older desktop builds into an unhealthy state.
Microsoft said the impact appears limited to the desktop client, with no indication that web or mobile users were affected. The company reported that its automated recovery system helped remediate the issue, then fully rolled back the problematic update and monitored telemetry and customer feedback to confirm recovery. Impacted users were instructed to fully quit and restart Teams so the reverted configuration could propagate, though Microsoft did not disclose how many customers or regions were affected.
See real exploitation activity before you spend the cycle.
3 events from the most recent confirmed update back to the earliest known activity.
Microsoft fully reverted the service update responsible for the launch failures and monitored telemetry and customer feedback to confirm recovery. The company instructed impacted users to fully quit and restart the Teams desktop client so the reverted configuration could propagate.
Microsoft initially attributed the problem to a transient service infrastructure issue and said its automated recovery system was remediating affected clients. The company classified the event as an incident, indicating noticeable customer impact.
A recent Microsoft Teams service update introduced a regression in the client build-caching system, pushing some older desktop client builds into an unhealthy state. Affected users were unable to launch Teams, became stuck on a loading screen, and saw an error message; Microsoft tracked the issue as incident TM1283300.
See real exploitation activity behind this advisory so you can triage it against everything else in the queue.
2 references tracked. Mallory keeps watching after this page renders.
Map indicators from this story to your assets and identify affected systems in minutes.
Every observed campaign, victim, and pivot linked to actors named in this story.
Malware, exploits, and IOCs connected to the activity described here.
YARA, Sigma, and Snort rules deployed to your SIEM as soon as they’re published.
Get matching new stories delivered to your team as they break — not the next morning.
Ask questions about this story and take action on the answers.
Other stories Mallory is tracking that overlap on entities, sources, or topic labels.
Microsoft experienced a broad service disruption that affected **SharePoint**, **Teams**, **Excel**, the **Microsoft 365 Admin Center**, and Azure-hosted workloads, with users also reporting failures in **Dynamics 365**, **Dataverse**, Entra join operations, and administrative portals. Administrators said SharePoint timeouts, Teams image-loading failures, and unreachable Azure virtual machines were especially visible in **West US**, **Canada West**, and parts of **US East**, while Downdetector recorded a sharp spike in complaints. Microsoft acknowledged the incident and directed customers to service health alert `MO1437424`, saying it was investigating increased reports and reviewing telemetry to determine scope and impact. The disruption appeared to extend beyond core collaboration services into dependent platforms and Microsoft-backed update infrastructure. Sysadmins reported **Windows Media Creation Tool** failures with error `0x80072EE4 - 0x20000`, Windows feature enablement errors such as `0x80244022`, and **Windows Update** failures returning `0x801901f7` on newly imaged systems. A separate outage report also indicated **KaseyaOne** login issues that users linked to the Azure problems, suggesting downstream impact on third-party services hosted on Microsoft infrastructure as customers saw intermittent outages, degraded functionality, and some signs of partial recovery.
Jul 24, 2026
Microsoft reported a service incident impacting **Microsoft 365** core services, with users experiencing connectivity issues and service degradation across **Exchange Online**, **Microsoft Teams**, and the broader M365 suite. The incident was tracked as `MO1220495`, with Microsoft stating it was still in the *investigating/diagnostic* phase and providing no estimated time to resolution; organizations were directed to monitor the Microsoft 365 Service Health Dashboard for tenant-specific impact details. Separately, Microsoft published guidance for a client-side stability issue where the classic **Outlook desktop** app can freeze/hang after installing recent Windows security updates (notably `KB5074109`, and also `KB5073724`), particularly affecting POP accounts and scenarios where Outlook `PST` files are stored on cloud-backed storage such as **OneDrive**. Recommended mitigations included using webmail, moving `PST` files off OneDrive, or uninstalling the problematic updates while Microsoft investigates. A third item describing “Microsoft data breach” and “zero-day vulnerabilities” is largely a repackaged Patch Tuesday/vulnerability roundup and does not substantively align with the M365 service incident or the Outlook-freeze regression.
Jun 29, 2026
Microsoft Teams experienced widespread outages, with users across the United States, Europe, and other regions reporting delays in sending messages and problems with other service functions. Microsoft acknowledged the issue publicly, stating that they were investigating the cause and observing signs of recovery, but did not initially provide a root cause or timeline for full restoration. The outage disrupted communication for many organizations relying on Teams for collaboration and messaging. Separately, a significant outage affected Microsoft 365 services—including Teams, Outlook, OneDrive, and the Copilot AI assistant—in Japan and China. This disruption was traced to a critical routing misconfiguration in Microsoft's infrastructure, which isolated healthy systems and led to intermittent login failures, degraded performance, and app loading errors. Microsoft confirmed that the incident was not the result of a cyberattack and reported that engineers had rebalanced traffic to restore service, with no data loss or security breaches identified. The outages caused notable business disruption in the affected regions, particularly for organizations dependent on Microsoft’s cloud ecosystem for daily operations.
Jun 29, 2026