[Bug] WAM credentials error 3399680404, 55793641

[DoctorWiz]

Library version used

Visual Studio

.NET version

6,7,8,9,10

Scenario

PublicClient - desktop app

Is this a new or an existing app?

The app is in production, I haven't upgraded MSAL, but started seeing this issue

Issue description and reproduction steps

Cannot get Visual Studio 2022 v17.14.14 to sign in. Getting:
WAM Error
Error Code: 3399680404
Error Message: NoNetwork
WAM Error Message: The server has not found anything matching the requested URI (Uniform Resource Identifier).
Internal Error Code: 557973641
Possible cause: no internet connection

But my network and internet are working just fine (I'm entering this bug report, duh!)
I am signed into GitHub in Visual Studio (no problem there).
Possibly related: When I try to submit a problem on the Visual Studio developer site, and I am clearly signed in with my Microsoft account, it keeps prompting me to sign in, and reporting:
Error signing in "

4E72D36F-AadAccountProviderService-21876-yypzkhfb-1.log

Relevant code snippets

Expected behavior

No response

Identity provider

Microsoft Entra ID (Work and School accounts and Personal Microsoft accounts)

Regression

No response

Solution and workarounds

No response

[github-actions]

Here are some similar issues that might help you. Please check if they can solve your problem.

• [Bug] Unable to authenticate using WAM Broker with enabled system proxy #4385
• [Bug] Login problems points to no internet connection #4721

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Possible solution (Extracted from existing issue, might be incorrect; please verify carefully)

Solution 1:

WAM requires a device-wide proxy to be used. To configure this, disable per-user proxy settings by setting the following registry key:

HKLM\Software\Policies\Microsoft\Windows\CurrentVersion\InternetSettings
ProxySettingsPerUser, type: REG DWORD,
0: per-machine proxy
1 (or key doesn’t exist): per-user (account) proxy

Additionally, configure the proxy using the admin console:

netsh winhttp set proxy proxy-server="http=127.0.0.1:8888;https=127.0.0.1:8888"

To verify the settings, run:

netsh winhttp show proxy

Reference:

• [Bug] Unable to authenticate using WAM Broker with enabled system proxy #4385 (comment)

Solution 2:

Ensure that loopback exemptions are in place. Open Fiddler, go to Tools --> Win8 Loopback Exemptions, and tick the exemption for Windows.AAD.BrokerPlugin (it may appear as 'Work or school account' or '@{Microsoft.AAD.BrokerPlugin...'). Click on [Save Changes].

Reference:

• [Bug] Unable to authenticate using WAM Broker with enabled system proxy #4385 (comment)
• [Bug] Unable to authenticate using WAM Broker with enabled system proxy #4385 (comment)

Solution 3:

If MSAL is not updated and this issue started happening suddenly, it might point to an Entra ID service endpoint issue. Check the network configuration and ensure there are no connectivity issues.

Reference:

• [Bug] Login problems points to no internet connection #4721 (comment)
• [Bug] Login problems points to no internet connection #4721 (comment)

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