Teams error CAA70004, explained and fixed
CAA70004 appears at sign-in with wording that the request could not be completed. In practice it means Teams sent its sign-in request and never got a workable response: the network path, a VPN or TLS-inspecting firewall, the local cache, or the PC's clock got in the way. It is a transport problem far more often than an account problem, which the web test below separates in one minute.
The fix, in order
- Test Teams on the web. Open teams.microsoft.com in the browser and sign in. If the web version works, the account is fine and everything after this step is about the desktop app and this PC's path to the servers.
- Check the system clock. Sign-in tokens are time-sensitive. In Settings, Time and language, enable Set time automatically and click Sync now. A clock off by more than a few minutes fails authentication in ways that look like network errors.
- Clear the Teams cache. Fully exit Teams (right-click the tray icon, Quit), then delete the contents of %appdata%\Microsoft\Teams for the classic app. For the new Teams, reset the app in Settings, Apps, Microsoft Teams, Advanced options, Reset. Restart and sign in.
- Bypass VPN and test the firewall. Disconnect any VPN and retry; VPN and TLS-inspection products that intercept encrypted traffic are a documented cause of this code family. If it works off VPN, the VPN configuration needs a Microsoft 365 bypass rather than a Teams fix.
- Enable TLS 1.2. Run inetcpl.cpl, Advanced tab, confirm Use TLS 1.2 is enabled. Teams sign-in endpoints refuse older TLS versions, and hardened or older Windows images sometimes have 1.2 off.
- Remove stored credentials and sign in fresh. Credential Manager, Windows Credentials, remove Microsoft Teams and Office entries, then sign in again. Finish by updating Teams or reinstalling it from Microsoft's site if the error survives a clean cache and clean credentials.
If it still happens
If the whole organization hits CAA70004 together, check Microsoft's service health first; sign-in service incidents present exactly like this. A single user on a managed device who fails while colleagues succeed is usually that device's proxy, certificate inspection, or conditional-access state, which the IT team can see in the sign-in logs.
Common questions
What is the difference between CAA70004 and CAA20002? They are cousins in the same sign-in failure family. CAA20002 is tied more closely to the authentication exchange itself and cached credentials, while CAA70004 points at the request not completing, the network path, TLS, or a server response that never arrived. The fix ladders overlap heavily.
Does reinstalling Teams fix CAA70004? Only when the app files themselves are damaged. Most cases are cache, credential, clock, or network path, all of which a reinstall leaves untouched, so work the earlier steps first.
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