80080300
Microsoft Teams Software
Severity: ModerateWhat Does This Error Mean?
Teams error 80080300 with the message 'Sorry, we've run into an issue' is the catch-all error the app shows when something below the network layer goes wrong — usually a corrupted credential, an expired certificate, or a Group Policy that blocks the WAM broker.
It is not a server-side outage in most cases.
The fix is to wipe the cached credential, restart the WAM broker, then sign back in.
Affected Models
- Microsoft Teams desktop on Windows 10 and 11
- Microsoft Teams 'classic' (V1)
- New Teams 2.0
- Domain-joined PCs with strict GPO settings
Common Causes
- Stale or corrupted credential in Windows Credential Manager
- Expired or revoked client certificate on the PC
- Microsoft Account Sign-In Assistant service stopped
- Group Policy blocking 'Allow Microsoft accounts to be optional'
- Network change while a token request was mid-flight
How to Fix It
-
Remove the Teams entry from Credential Manager.
Open Control Panel → User Accounts → Credential Manager → Windows Credentials.
Look for any entry that starts with msteams_, MicrosoftAccount:, or microsoftofficeXX_data.
Click each and choose Remove.
This forces Teams to ask for a fresh password instead of replaying a broken one. -
Restart the Microsoft Account Sign-In Assistant service.
Press Win+R, type services.msc, hit Enter.
Find 'Microsoft Account Sign-In Assistant'.
Right-click and pick Restart.
If Startup type is set to Disabled, change it to Manual (Trigger Start) — Group Policy sometimes turns this off and breaks Teams entirely. -
Reset the Teams app data.
Quit Teams.
For new Teams: Settings → Apps → Installed apps → find Microsoft Teams → click Advanced options → Reset.
For classic Teams: delete the folder at %appdata%\Microsoft\Teams.
Reopen Teams. The first launch is slower than usual. -
Check Group Policy if you are on a work PC.
Press Win+R, type rsop.msc.
Look under Computer Configuration → Windows Settings → Security Settings → Local Policies → Security Options.
If 'Accounts: Block Microsoft accounts' is set to 'Users can't add or log on with Microsoft accounts', that breaks Teams.
Ask IT to relax this for your account or switch you to AAD-only sign-in.
Frequently Asked Questions
Is 80080300 a Microsoft outage?
Rarely.
Check status.office.com — if there's no Teams incident listed, the problem is local.
Microsoft outages usually show different errors (CAA-prefixed) and clear within 30-60 minutes once status is updated.
An 80080300 that lasts hours and is just on your PC is local.