Microsoft Entra ID
A Microsoft Entra identity service that provides identity management and access control capabilities. Replaces Azure Active Directory.
23,513 questions
.net Blazor app stuck on on B2C Redirect Url
![](data:image/svg+xml, %3Csvg xmlns='http://www.w3.org/2000/svg' height='64' class='font-weight-bold' style='font: 600 30.11764705882353px "SegoeUI", Arial' width='64'%3E%3Ccircle fill='hsl(19.2, 59%, 11%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3EMS%3C/text%3E%3C/svg%3E)
Matthew Scheetz
0
Reputation points
I've got a Blazor Server app (.net 8). It is using B2C for authentication and is behind an application gateway.
After successful login, some users are getting redirected to the redirect url: https://example.com/signin-oidc
the app gets stuck here and users are presented with Correlation Error.
If user updates the url and removes signin-oidc so they are now just going to https://example.com they are successfully logged in to the home page.
My B2C configs are configured as so:
"AzureAdB2C": {
"Instance": "https://my-b2c.b2clogin.com",
"ClientId": "",
"Domain": "my-b2c.onmicrosoft.com",
"ObjectId": "",
"TenantId": "",
"ClientSecret": "",
"CallbackPath": "/signin-oidc",
"SignUpSignInPolicyId": "B2C_1_MyB2C_SignIn",
"SignedOutCallbackPath": "/signout"
}
B2C is configured with https://example.com/signin-oidc as a redirect url.
The strange thing is that this does not happen for every user at every login.
{count} votes
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![](data:image/svg+xml, %3Csvg xmlns='http://www.w3.org/2000/svg' height='64' class='font-weight-bold' style='font: 600 30.11764705882353px "SegoeUI", Arial' width='64'%3E%3Ccircle fill='hsl(278.4, 45%, 36%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3EAV%3C/text%3E%3C/svg%3E)
Akhilesh Vallamkonda 12,415 Reputation points Microsoft External Staff2025-03-03T22:49:19.7833333+00:00 Hi @Matthew Scheetz
Thank you for reaching Microsoft Q&A Forum!
Based on the information you provide it seems the issue is with the redirect URI, could you please verify that the redirect URI configured in your Azure AD B2C tenant should matches the application URI. -
Matthew Scheetz 0 Reputation points
2025-03-03T23:35:37.6933333+00:00 Yes, they match
-
Matthew Scheetz 0 Reputation points
2025-03-03T23:37:06.8666667+00:00 Yest, they match
-
Akhilesh Vallamkonda 12,415 Reputation points Microsoft External Staff
2025-03-04T14:45:04.9333333+00:00 Hi @Matthew Scheetz
In you Blazor app try to add the below line and see if the issue is fixed.
<TrimmerRootAssembly Include="Microsoft.AspNetCore.Components.WebAssembly.Authentication" /> -
Matthew Scheetz 0 Reputation points
2025-03-04T16:36:11.59+00:00 Even on Blazor Server app?
-
Akhilesh Vallamkonda 12,415 Reputation points Microsoft External Staff
2025-03-04T22:05:17.6166667+00:00 Hi @Matthew Scheetz
This has to be update in your application, if you don't have option to update kindly approach your application team and explain the scenario. -
Matthew Scheetz 0 Reputation points
2025-03-04T22:46:09.9733333+00:00 Ok i added to the my .csproj
<Project Sdk="Microsoft.NET.Sdk.Web"> <PropertyGroup> <TargetFramework>net8.0</TargetFramework> <Nullable>enable</Nullable> <ImplicitUsings>enable</ImplicitUsings> <Version>1.0.5</Version> </PropertyGroup> <ItemGroup> <TrimmerRootAssembly Include="Microsoft.AspNetCore.Components.WebAssembly.Authentication" /> </ItemGroup> .... </Project>I'm still getting stuck at
https://example.com/signin-oidcWhen i delete
/signin-oidcfrom the browser so that it is justhttps://example.comI get forwarded to login.microsoft.com and the full url i'm sent to is:The call back url is
https://example.b2clogin.com/example.onmicrosoft.com/oauth2/authresp, it is no longerhttps://example.com/signin-oidc. I am then immediately sent tohttps://example.comand logged in. -
![](data:image/svg+xml, %3Csvg xmlns='http://www.w3.org/2000/svg' height='64' class='font-weight-bold' style='font: 600 30.11764705882353px "SegoeUI", Arial' width='64'%3E%3Ccircle fill='hsl(166.4, 27%, 26%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3ERP%3C/text%3E%3C/svg%3E)
Raja Pothuraju 15,555 Reputation points Microsoft External Staff2025-03-05T15:34:50.3366667+00:00 Hello @Matthew Scheetz,
Thank you for sharing more details on this.
Based on the provided information, it appears that the issue originates from the application side. When users access the URL
https://example.com/signin-oidc, they sometimes encounter a failure that leads to the error: "An unhandled exception occurred while processing the request." This exception seems to happen even before any request is made to Azure AD B2C.When the application works correctly, does it successfully redirect users to login.microsoft.com? Also, what is the redirect URI for the request when it work as expected?
Regarding the URL
https://{your-tenant-name}.b2clogin.com/{your-tenant-name}.onmicrosoft.com/oauth2/authresp, redirecting to this endpoint is expected when configuring your application in the identity provider. This ensures the identity provider properly routes authentication requests back to Azure AD B2C.I recommend reviewing the following documentation and verifying how your application handles authentication requests:
Configure authentication in a sample web app (Azure AD B2C)
Configure OIDC authentication in an ASP.NET Core web app
Secure a Blazor WebAssembly app with OIDC
Additionally, if possible, try capturing Fiddler or Network trace logs when the issue occurs on the user’s end. This would help in identifying where the failure is happening.
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