Fix New Teams Migration Does Not Complete after Upgrading to New Teams

After upgrading to the new Microsoft Teams desktop app, some users see the migration stuck at a partial state. The app shows a progress bar that never finishes, or it reverts to the classic Teams client. This happens when the migration engine cannot move your chat history, files, and settings from the old Teams cache to the new app. This article explains the root cause of the incomplete migration and gives you step-by-step fixes to force the migration to finish.

You will also learn how to clear the migration state, repair the new Teams installation, and avoid common pitfalls that block the process. The fixes apply to Windows 11 and Windows 10 machines where you upgraded from classic Teams to new Teams.

Why the New Teams Migration Stops Before Completion

The migration from classic Teams to new Teams copies your local data into a new storage location. This includes your chat history, meeting recordings, files, and app settings. The migration engine checks for existing classic Teams data and then moves it to the new Teams cache folder. When the process fails, it usually leaves a partial copy and a flag that says the migration is still in progress.

The most common trigger is a leftover classic Teams process running in the background. The new Teams installer cannot overwrite files that are locked by the old client. Another cause is a corrupted migration state value in the Windows registry. If the migration state is set to a value other than 0, the new Teams app thinks the migration already finished and skips the remaining steps.

A third cause is an outdated version of the new Teams app. Microsoft updates the migration logic frequently. If your installed version has a bug, the migration will stall. Finally, a slow or disconnected network can interrupt the download of the new Teams components, leaving the migration half-done.

How the Migration State Works

The migration state is stored in the registry under HKCU\Software\Microsoft\Teams\MigrationState. A value of 0 means no migration is needed. A value of 1 means the migration is in progress. A value of 2 means the migration completed successfully. If you see a value of 1 that stays for more than an hour, the migration is stuck.

Steps to Force the New Teams Migration to Complete

Before you start, close all Teams windows. Also close Outlook and any other app that might use Teams integration. Then follow these steps in order.

1. End all Teams processes
   Press Ctrl + Shift + Escape to open Task Manager. In the Processes tab, look for any entry named Microsoft Teams. Right-click each entry and select End task. Do the same for any process named TeamsUpdater or TeamsMachineInstaller.
2. Reset the migration state in the registry
   Press Win + R, type regedit, and press Enter. Navigate to HKEY_CURRENT_USER\Software\Microsoft\Teams. Double-click the value named MigrationState. If it does not exist, right-click in the right pane, select New > DWORD (32-bit) Value, and name it MigrationState. Set the value to 0 and click OK. Close Registry Editor.
3. Clear the new Teams cache folder
   Open File Explorer and paste this path in the address bar: %localappdata%\Packages\MSTeams_8wekyb3d8bbwe\LocalCache\Microsoft\Teams. Select all files and folders inside and press Delete. If a file is in use, skip it and continue.
4. Run the new Teams repair installer
   Download the latest new Teams installer from the Microsoft 365 admin center or from the official Teams download page. Run the installer with the command line flag /repair. To do this, open Command Prompt as administrator, navigate to the folder where you saved the installer, and type the installer name followed by /repair. For example: Teams_windows_x64.exe /repair.
5. Restart the new Teams app
   Launch new Teams from the Start menu or from the taskbar. The app will detect the reset migration state and start the migration again. Wait for the progress bar to reach 100 percent. This can take from a few minutes to an hour depending on the size of your data.
6. Verify the migration completed
   After the progress bar disappears, click your profile picture and select Settings. Go to About and check the version number. Then open a chat and confirm your message history is present. Also check your Files tab in any team to see if your documents are there.

If the Migration Still Does Not Complete

If the migration fails again, you can force a full reinstall of new Teams. Uninstall new Teams from Settings > Apps > Installed apps. Then download the latest version and install it fresh. After installation, sign in with your work or school account. The app will attempt the migration again.

If Teams Still Has Issues After the Main Fix

Teams Reverts to Classic After the Migration

If the app switches back to classic Teams, the migration state is still set to 1. Repeat the registry reset in step 2, but this time also delete the entire Teams folder under HKEY_CURRENT_USER\Software\Microsoft. Then restart the PC and open new Teams.

Chat History Is Missing After Migration

The migration copies chat data from the classic Teams cache. If your chat history is missing, the cache was likely corrupted. Close Teams and delete the folder %appdata%\Microsoft\Teams. This removes the old cache. Then restart new Teams and sign in again. Your chat history will re-sync from the server.

Files Are Not Available in the New Teams App

Files are stored in SharePoint and OneDrive, so they should appear after the migration. If they do not, check the Teams admin center. Go to Teams admin center > Teams apps > Manage apps > New Teams. Look for any policy that blocks file access. Also verify that the user has a valid license for SharePoint Online.

New Teams Desktop vs Classic Teams: Key Differences

Item	New Teams Desktop	Classic Teams Desktop
Architecture	Built on WebView2 and React	Built on Electron
Performance	Uses less memory and CPU	Higher resource usage
Migration state	Uses registry value MigrationState	No migration state
Installation	Per-user installer in Packages folder	Machine-wide installer
Update frequency	More frequent updates	Monthly updates

You now know how to reset the migration state, clear the cache, and repair the installation. Run the repair installer first, then reset the registry value if the problem persists. After the migration completes, check your chat history and files to confirm everything moved correctly. Use the Teams admin center to monitor migration status for all users in your organization. For a faster migration, disable the classic Teams auto-start policy before the upgrade.