Most common problems

There was a problem with authorization

Teams cannot authenticate. The cause is usually conflicting accounts or an incorrect system clock.

Conditional Access blocked sign-in

A Conditional Access policy in your tenant denies sign-in. Common for devices that do not meet compliance requirements.

Device enrollment conflicts with license

Conflict between the Intune enrollment policy and the assigned license. Often appears after license changes or tenant migrations.

Token could not be refreshed

Teams cannot refresh the auth token and reports 0xCAA70004. A clean sign-in reset usually fixes it.

Request timed out

Teams gets no response from the Microsoft server within the allowed time. Usually a sign of latency, packet loss, or proxy issues.

Could not reach the server

Teams cannot reach Microsoft during sign-in. Classic network symptom, often caused by firewall or DNS.

Keyset does not exist (TPM)

Teams cannot start because the connection to the TPM chip fails. This affects many corporate laptops.

Application not found in tenant

Entra reports the Teams app is not registered in the tenant. Common with guest accounts or migrated tenants.

Silent sign-in failed

Teams could not re-authenticate without user interaction. Sign in once manually, then silent renewal works again.

Fresh sign-in required

Microsoft Entra requires a full new sign-in because important account properties changed since the last login.

Access blocked by Conditional Access

A Conditional Access policy explicitly denies sign-in. Unlike 0xCAA20004, this rule states the exact block reason.

Admin consent required

Teams or an integrated app requests permissions only a global admin can grant.

Could not connect to Microsoft servers

Teams reports CAA20002 during sign-in. Usually caused by a blocked network, outdated TLS settings, or a corrupted token cache.

Maximum retry count exceeded

Teams has tried to sign in too many times without success. The client waits until a reset happens.

We are sorry, we have run into an issue

Teams will not start and shows a generic error without a code. Here is how to find the real cause.