Teams · Fix-itDraft

Teams won't sign in or keeps looping

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Teams opens, you enter your email and password, and it sends you right back to the sign-in screen. Or the window stays blank. This is usually a stale local sign-in, a damaged cache, or a work account policy, not a broken mailbox.

These steps are for the current Teams desktop app on Windows (new Teams). Confirm the password works in a browser first, then reset or clear the app’s local data and sign in once. They don’t change your Microsoft password.

If this is a work or school account and your company requires a compliant device, Conditional Access, or a new MFA enrollment, the local steps may not override that. You’ll need your admin after you’ve tried the basics.

Before you start

  1. Confirm the password actually works. In a browser, open https://teams.microsoft.com and sign in. If that fails, fix the password or MFA first. The desktop app will keep failing until the web sign-in works.
  2. Fully quit Teams. Right-click the Teams icon in the taskbar or notification area and choose Quit. Closing the window isn’t enough, because Teams often keeps running in the background. If it is still listed in Task Manager, end the Microsoft Teams tasks.
  3. Check that the PC’s date and time are correct. Open Settings > Time & language > Date & time, and turn on Set time automatically. A badly wrong clock can interfere with sign-in tokens.
  4. If you can, sign in to Outlook or Office.com with the same account. That tells you whether the problem is unique to the Teams app on this PC.

To tell new Teams from classic Teams: the current app is simply named Microsoft Teams. Classic Teams is the older app Microsoft has been retiring. Use new Teams, and follow the new Teams cache steps below. Only use the classic cache path if you still have classic Teams installed.

1. Reset the Teams app in Windows Settings

Microsoft documents a reset as the first way to clear new Teams on Windows. Reset deletes local app data, including personalization you’ve set in the app. You’ll sign in again afterward.

  1. Quit Teams completely, as above.
  2. Open Settings > Apps > Installed apps.
  3. Search for Microsoft Teams.
  4. Select the More options button (…) next to it, then Advanced options.
  5. If you see Repair, you can try that first. It attempts a fix without wiping app data.
  6. If Repair doesn’t help, select Reset, then confirm.
  7. Open Teams and sign in with the account that already works on the web. Finish any MFA prompt.

The first launch after a reset can take longer than usual.

2. Clear the new Teams cache by hand

If a reset didn’t help, delete the cache files Microsoft documents for new Teams.

  1. Quit Teams again. Confirm it’s gone in Task Manager.

  2. Press Windows + R, paste this path, and press Enter:

    %userprofile%\appdata\local\Packages\MSTeams_8wekyb3d8bbwe\LocalCache\Microsoft\MSTeams

  3. Delete all files and folders inside that directory. Don’t delete your Documents or Downloads.

  4. If Windows says a file is in use, Teams is still running. End the Teams tasks and try again.

  5. Open Teams and sign in.

Microsoft notes that after you clear the cache, Teams can take longer to start because it has to rebuild those files.

If you still have classic Teams (uncommon now), Microsoft’s classic cache path is %appdata%\Microsoft\Teams. Don’t clear that folder expecting it to fix new Teams. It belongs to the old app.

3. Clear stale Teams or Office sign-ins

Windows may still be handing Teams an old token.

  1. Press the Windows key, type Credential Manager, and open it.
  2. Check Windows Credentials and Generic Credentials (and Web Credentials if you see that section).
  3. Remove entries that clearly belong to Teams, Microsoft 365, Office, or your work sign-in, similar to the steps in Outlook keeps asking for my password.
  4. Open Teams and sign in again.

You’re only deleting the saved copy on this PC. Other Office apps may ask you to sign in once. That’s expected.

4. If it still loops

Do these in order. Stop when Teams stays signed in.

Try Teams in the browser

Use https://teams.microsoft.com so you can get into meetings and chats while you keep working on the desktop app. If the browser works, the account is fine and the problem is local to this PC.

Check a work or school account on the PC

Go to Settings > Accounts > Access work or school. If the account is listed but in a broken state, some organizations want you to disconnect and add it again. Only do that if you’re allowed to reconnect it yourself. If Disconnect is blocked or your company requires the device to stay enrolled, stop and ask your admin.

Sign out of other Office apps and try again

Close Outlook, Word, Excel, and OneDrive’s on-screen windows, then open Teams and sign in once. A stale Office sign-in can fight the new one.

Install updates, then restart

In Teams, open Settings and check for updates if the option is there. Also install pending Windows updates, restart the PC, and try once more.

Work account policies

If the web sign-in shows a message about a compliant device, an approved app, or a blocked location, the loop is probably policy, not a cache problem. Clearing the cache won’t bypass that. Send the exact message to your admin.

What not to do

  • Don’t keep re-entering a password that already fails on the web.
  • Don’t uninstall and reinstall Teams as the first step. Reset or cache clear is the documented starting point and is easier to undo.
  • Don’t download a “Teams repair” tool from a random site.

Still stuck?

If Teams still loops after a reset and a cache clear, I can connect remotely and look at the sign-in with you. Support is after-hours, nationwide, with local help in the Dallas–Fort Worth area. Details are on the Work with me page.

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