Microsoft Security | Microsoft Entra | Microsoft Entra ID
A cloud-based identity and access management service for securing user authentication and resource access
Sporadic failure to get to our .b2clogin.com URL on some networks
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Admin at PeriGenSolutions
0
Reputation points
We have mobile app that uses Azure B2C for customer IdP authentication.
When entering the username (email) to the app, the app redirects the authentication to Azure B2C with a dialog asking the user to redirect to B2C and proceed with authentication flow. On most devices, this works fine. However, on some devices / networks, the following message shows "The resource you are looking for has been removed, had its name changed, or is temporary unavailable.".
Some primary device having problems is an Android failing on AT&T or Wifi. Other devices fail on Wifi but are able to access on T-Mobile or Verizon. Some have no problem on Wifi or Cellular.
Those are all from the California coast area. We have many customer in the Utah area with no known similar problems (doubt its related but trying to provide all facts).
Any thought?
Microsoft Security | Microsoft Entra | Microsoft Entra ID
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Shubham Sharma 17,925 Reputation points Microsoft External Staff Moderator2026-05-22T01:33:09.0966667+00:00 Thank you for reaching out to Microsoft Q&A.
Why this issue is happening:-
1. The error message is misleading
The message:
“The resource you are looking for has been removed…”
is commonly returned by Azure B2C when:
Policy/tenant/URL is incorrect OR
The request never properly reaches the correct B2C endpoint
While misconfiguration is a common cause, in your case:
Same URL works on other networks
Fails only on certain ISPs/regions
This confirms the request is being altered, blocked, or misrouted before reaching B2C.
2. Network/DNS resolution issues
Intermittent failures limited to specific networks usually indicate:
ISP DNS resolution issues
CDN edge (Azure Front Door) routing inconsistencies
Network-level filtering/firewall/proxy blocking *.b2clogin.com
Similar cases show:
Some users unable to connect while others can
No errors in Azure logs (requests never reach service)
DNS/provider-specific failures
3. Regional / ISP-specific routing problems
Azure AD B2C uses globally distributed endpoints
Traffic is routed to nearest edge (via Azure Front Door/CDN)
If a specific ISP or region has:
DNS propagation issues
Cached incorrect records
Peering/routing problems
Only those users are impacted
Below are the Recommended Resolution
- Validate endpoint & configuration
Even though this is likely network-related, confirm:
Correct tenant format:
https://<tenant>.b2clogin.com/<tenant>.onmicrosoft.com/<policy>/oauth2/v2.0/authorize- Correct policy name (
p=or path-based) - Registered redirect URI matches exactly
For your reference:https://learn.microsoft.com/en-us/azure/active-directory-b2c/b2clogin
2. Perform network diagnostics
Ask affected users to:
Test DNS resolution:
nslookup <tenant>.b2clogin.com- Try different DNS:
- Google (8.8.8.8)
- Cloudflare (1.1.1.1)
- Test via browser:
https://<tenant>.b2clogin.com
If DNS fails or resolves differently → confirms ISP issue
3. Capture failing request details
Collect from affected users:
HAR trace / browser network logs
Public IP + ISP name
Exact failing URL
This helps confirm:
Whether the request reaches Azure
Whether it's blocked/redirection issue
4. Use a custom domain
To avoid ISP/CDN inconsistencies:
Configure a custom domain for B2C
Route via Azure Front Door
Example:
https://login.yourdomain.comBenefits:
- Better control over DNS resolution
- Reduced dependency on
b2clogin.comrouting - Improved consistency across ISPs
For your reference: https://learn.microsoft.com/en-us/azure/active-directory-b2c/b2clogin
5. Check Azure Service Health
Verify if any regional outage exists
Use Azure Service Health : https://azure.status.microsoft/en-us/status?service=active-directory-b2c
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Shubham Sharma 17,925 Reputation points Microsoft External Staff Moderator
2026-05-25T02:42:32.03+00:00 Following up to check if the resolution provided was helpful. Let us know if you need any further assistance.
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Admin at PeriGenSolutions 0 Reputation points
2026-05-26T03:51:26.8566667+00:00 Another clarification to the original scenario is that, from a browser, all users are able to connect to the B2C url: https://<company-name>.b2clogin.com/... but problem arise when trying to connect to the custom domain: https://login.<company-name>.com/...some can while others cannot. The actual app is a native mobile app.
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Shubham Sharma 17,925 Reputation points Microsoft External Staff Moderator
2026-05-26T06:07:45.1166667+00:00 Thank you for your reply.
Could you please confirm whether Azure Front Door is being used for the custom domain configuration?
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Shubham Sharma 17,925 Reputation points Microsoft External Staff Moderator
2026-05-27T02:36:34.2633333+00:00 Could you please provide an update?
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Admin at PeriGenSolutions 0 Reputation points
2026-06-01T03:12:34.6933333+00:00 Yes, Azure Front Door is used. For users who cannot access, we do not see any call in the AFD logs.
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Harshitha Eligeti 4,530 Reputation points Microsoft External Staff Moderator2026-08-03T17:42:44.7766667+00:00 Hello @Admin at PeriGenSolutions
Are you still encountering the issue? Let me know, and I can help further.
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