Microsoft Teams Won’t Open or Not Launching: How to Fix It

When Microsoft Teams refuses to open, it can bring your entire working day to a standstill. Whether the app freezes on the splash screen, vanishes without appearing at all, or simply does nothing when you click the icon, there are several well-established causes — and just as many reliable fixes. This guide walks through each one, covering both the classic Teams client and the new Teams experience.

Check Whether Teams Is Already Running

Before anything else, check your system tray (Windows) or menu bar (Mac). Teams often runs in the background after closing the window, which can prevent a second instance from launching. Right-click the Teams icon in the tray and choose Quit, then try opening Teams again.

On Windows, open Task Manager (Ctrl + Shift + Esc), look for any Teams processes under the Processes tab, right-click each one, and select End Task. Once all instances are closed, relaunch Teams.

Restart and Check for Windows or macOS Updates

Teams depends on components that are updated via Windows Update and macOS Software Update. An outdated operating system can cause compatibility issues that stop Teams from loading. Install any pending system updates, restart your machine, then try again.

Clear the Teams Cache

A corrupted cache is one of the most common causes of Teams failing to open. Clearing it forces Teams to rebuild its local data from scratch.

For a full walkthrough, see the guide on how to clear the Microsoft Teams cache. In brief:

Classic Teams (Windows)

1. Fully quit Teams via the system tray.
2. Press Windows + R and type %appdata%MicrosoftTeams.
3. Delete the contents of the following folders: Cache, blob_storage, databases, GPUCache, IndexedDB, Local Storage, tmp.
4. Relaunch Teams.

New Teams (Windows)

1. Fully quit Teams.
2. Navigate to %localappdata%PackagesMSTeams_8wekyb3d8bbweLocalCacheMicrosoftMSTeams.
3. Delete the Cache folder contents.
4. Relaunch Teams.

Mac (Classic Teams)

1. Quit Teams.
2. Open Finder, press Cmd + Shift + G, and go to ~/Library/Application Support/Microsoft/Teams.
3. Delete the Cache folder contents.
4. Relaunch Teams.

Repair or Reinstall Teams

If clearing the cache does not help, try repairing the installation.

Classic Teams (Windows)

1. Go to Settings > Apps > Apps & features.
2. Find Microsoft Teams and click Modify (if available) or Uninstall.
3. Download the latest installer from the Microsoft Teams download page.
4. Run the installer and relaunch Teams.

New Teams (Windows)

New Teams installs as an MSIX package. To reinstall it:

1. Open Settings > Apps > Installed apps and search for Teams.
2. Click the three-dot menu and choose Uninstall.
3. Reboot, then reinstall from the Microsoft Store or the Teams download page.

Check Your Antivirus or Firewall

Security software can occasionally block Teams from launching, particularly after an update changes the application’s binary signature. Temporarily disable your antivirus and try opening Teams. If it launches, add Teams as an exception in your security software settings.

If Teams loads but you have audio or call problems, see the guide on Microsoft Teams calls keep dropping for network-related fixes.

Check the Microsoft 365 Service Status

Sometimes Teams simply will not start because Microsoft’s authentication or presence services are down. Visit status.office365.com or check the Microsoft 365 admin centre for any active incidents. If there is a service outage, all you can do is wait for Microsoft to resolve it.

Run Teams as Administrator (Windows)

Right-click the Teams shortcut and select Run as administrator. This can resolve launch failures caused by permission issues, particularly on managed corporate devices.

Check the Teams Log Files

If Teams still will not open, the logs can tell you why. On Windows, press Windows + R and type %appdata%MicrosoftTeamslogs.txt to open the log file. Look for error messages near the bottom — common culprits include corrupted user profiles and missing dependencies such as the Microsoft Visual C++ Redistributable.

Create a New Windows User Profile

A corrupted Windows user profile can prevent Teams from initialising. To test this, create a new local user account on your machine, sign in as that user, and attempt to launch Teams. If it opens cleanly, your original profile is the problem. Microsoft’s support documentation covers how to copy data from a corrupted profile to a new one.

Related Troubleshooting

If Teams opens but performs poorly once it does, take a look at the guide on Microsoft Teams running slow or not loading. For problems with notifications not appearing after a relaunch, see Microsoft Teams notifications not working.

For a full index of every Teams guide and troubleshooting fix on Serverman, see the Microsoft Teams complete guide and troubleshooting hub.