Azure - Unhandled exception - Server Error in '/letsencrypt' Application

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Hi,
I have installed Azure Let's Encrypt version 1.0.7.
The certificate installation fails with the message reported below in its entirety.

It looks like the extension is trying to resolve a malformed URL, because the "scm" subdomain should precede the region subdomain (in my case: canadacentral-01) and not follow it.
For clarity:
https://hw-ai-chat-hwd2c3avadb7bfam.scm.canadacentral-01.azurewebsites.net/
is correct for my app and loads the Kudu page

https://hw-ai-chat-hwd2c3avadb7bfam.canadacentral-01.scm.azurewebsites.net/
does not exist and as expected the Azure Let's Encrypt extension fails to resolve it.

It is worth pointing out that at the previous stage before the error, the correct "scm" URL is listed in the "Hostname SSL bindings" section.

Any advice would be appreciated, thank you.

Full error

Server Error in '/letsencrypt' Application.

The remote name could not be resolved: 'hw-ai-chat-hwd2c3avadb7bfam.canadacentral-01.scm.azurewebsites.net'

Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.Net.WebException: The remote name could not be resolved: 'hw-ai-chat-hwd2c3avadb7bfam.canadacentral-01.scm.azurewebsites.net'

Source Error:

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.

Stack Trace:

`[WebException: The remote name could not be resolved: 'hw-ai-chat-hwd2c3avadb7bfam.canadacentral-01.scm.azurewebsites.net']
System.Net.HttpWebRequest.EndGetRequestStream(IAsyncResult asyncResult, TransportContext& context) +581
System.Net.Http.HttpClientHandler.GetRequestStreamCallback(IAsyncResult ar) +107

[HttpRequestException: An error occurred while sending the request.]
System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) +102
System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) +64
LetsEncrypt.Azure.Core.d__11.MoveNext() in J:\Projects\letsencrypt-siteextension\LetsEncrypt.SiteExtension.Core\KuduRestClient.cs:67
System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) +102
System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) +64
LetsEncrypt.Azure.Core.Services.d__7.MoveNext() in J:\Projects\letsencrypt-siteextension\LetsEncrypt.SiteExtension.Core\Services\KuduFileSystemAuthorizationChallengeProvider.cs:53
System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) +102
System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) +64
LetsEncrypt.Azure.Core.Services.d__5.MoveNext() in J:\Projects\letsencrypt-siteextension\LetsEncrypt.SiteExtension.Core\Services\KuduFileSystemAuthorizationChallengeProvider.cs:37
System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) +102
System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) +64
LetsEncrypt.Azure.Core.Services.d__5.MoveNext() in J:\Projects\letsencrypt-siteextension\LetsEncrypt.SiteExtension.Core\Services\BaseHttpAuthorizationChallengeProvider.cs:53
System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) +102
System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) +64
LetsEncrypt.Azure.Core.Services.d__5.MoveNext() in J:\Projects\letsencrypt-siteextension\LetsEncrypt.SiteExtension.Core\Services\AcmeService.cs:55
System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) +102
System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) +64
LetsEncrypt.Azure.Core.d__14.MoveNext() in J:\Projects\letsencrypt-siteextension\LetsEncrypt.SiteExtension.Core\CertificateManager.cs:210
System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) +102
System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) +64
LetsEncrypt.Azure.Core.d__15.MoveNext() in J:\Projects\letsencrypt-siteextension\LetsEncrypt.SiteExtension.Core\CertificateManager.cs:234
System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) +102
System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) +64
LetsEncrypt.SiteExtension.Controllers.d__7.MoveNext() +596
System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) +102
System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) +64
System.Web.Mvc.Async.TaskAsyncActionDescriptor.EndExecute(IAsyncResult asyncResult) +97
System.Web.Mvc.Async.<>c__DisplayClass8_0.b__1(IAsyncResult asyncResult) +17
System.Web.Mvc.Async.WrappedAsyncResult1.CallEndDelegate(IAsyncResult asyncResult) +10 System.Web.Mvc.Async.WrappedAsyncResultBase1.End() +48
System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeActionMethod(IAsyncResult asyncResult) +32
System.Web.Mvc.Async.<>c__DisplayClass11_0.b__0() +58
System.Web.Mvc.Async.<>c__DisplayClass11_2.b__2() +228
System.Web.Mvc.Async.<>c__DisplayClass7_0.b__1(IAsyncResult asyncResult) +10
System.Web.Mvc.Async.WrappedAsyncResult1.CallEndDelegate(IAsyncResult asyncResult) +10 System.Web.Mvc.Async.WrappedAsyncResultBase1.End() +48
System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeActionMethodWithFilters(IAsyncResult asyncResult) +34
System.Web.Mvc.Async.<>c__DisplayClass3_6.b__4() +35
System.Web.Mvc.Async.<>c__DisplayClass3_1.b__1(IAsyncResult asyncResult) +100
System.Web.Mvc.Async.WrappedAsyncResult1.CallEndDelegate(IAsyncResult asyncResult) +10 System.Web.Mvc.Async.WrappedAsyncResultBase1.End() +48
System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeAction(IAsyncResult asyncResult) +27
System.Web.Mvc.<>c.b__152_1(IAsyncResult asyncResult, ExecuteCoreState innerState) +11
System.Web.Mvc.Async.WrappedAsyncVoid1.CallEndDelegate(IAsyncResult asyncResult) +29 System.Web.Mvc.Async.WrappedAsyncResultBase1.End() +48
System.Web.Mvc.Controller.EndExecuteCore(IAsyncResult asyncResult) +45
System.Web.Mvc.<>c.b__151_2(IAsyncResult asyncResult, Controller controller) +13
System.Web.Mvc.Async.WrappedAsyncVoid1.CallEndDelegate(IAsyncResult asyncResult) +22 System.Web.Mvc.Async.WrappedAsyncResultBase1.End() +48
System.Web.Mvc.Controller.EndExecute(IAsyncResult asyncResult) +26
System.Web.Mvc.Controller.System.Web.Mvc.Async.IAsyncController.EndExecute(IAsyncResult asyncResult) +10
System.Web.Mvc.<>c.b__20_1(IAsyncResult asyncResult, ProcessRequestState innerState) +28
System.Web.Mvc.Async.WrappedAsyncVoid1.CallEndDelegate(IAsyncResult asyncResult) +29 System.Web.Mvc.Async.WrappedAsyncResultBase1.End() +48
System.Web.Mvc.MvcHandler.EndProcessRequest(IAsyncResult asyncResult) +28
System.Web.Mvc.MvcHandler.System.Web.IHttpAsyncHandler.EndProcessRequest(IAsyncResult result) +9
System.Web.CallHandlerExecutionStep.InvokeEndHandler(IAsyncResult ar) +132
System.Web.CallHandlerExecutionStep.OnAsyncHandlerCompletion(IAsyncResult ar) +126`

3

I fixed it. I don't have a suggestion for your problem but agree the URL got mangled :slight_smile:

3 Likes
4

@AndreaHS I am not an Azure expert but wanted to post given there hasn't been other replies.

My first comment is the docs for that extension say this:

Important

You should migrate off this extension and instead use the free SSL certificates offered by Microsoft Install a TLS/SSL certificate for Your App - Azure App Service | Microsoft Learn If you feel like you still need the extension, let me know why.

That looks like a bad idea to start using it today. And, if you need help with it you might try posting at its github: GitHub - sjkp/letsencrypt-siteextension: Azure Web App Site Extension for easy installation and configuration of Let's Encrypt issued SSL certifcates for custom domain names.

Lastly, if you explain what you are trying to do we might have suggestions for other options too.

4 Likes