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BrandonMcAlees-7456 avatar image
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BrandonMcAlees-7456 asked ·

App startup fails on F1 and D1 instances, but works on B1, S1 and above?

Code runs fine locally in debug and release mode. Deployed to an S1 or B1 App Service it also runs fine. Recently, without any code changes, my D1 App Service stopped working out of the blue. When I try to access the site, I get a 502.5 ANCM Out-Of-Process Startup Failure.

So I enabled stdout and got the following log...

System.InvalidOperationException: Unable to resolve service for type 'Microsoft.AspNetCore.Identity.IUserStore\`1[XXXXX.Domain.Authentication.ApplicationUser]' while attempting to activate 'Microsoft.AspNetCore.Identity.UserManager\`1[XXXXX.Domain.Authentication.ApplicationUser]'.

Like I said, nothing changed with the code or my Azure App Service in the past 2 months, however, this started happening two days ago. Why would I just now start receiving this error and why does it work on an S1? Also, I've looked at metrics and my quotas are nowhere close to being hit. The site has an average of between 2-8 users a day.





azure-webapps
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1 Answer

SnehaAgrawal-MSFT avatar image
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SnehaAgrawal-MSFT answered ·

Thanks for asking question! The cause of a process startup failure can usually be determined from entries in the Application Event Log and the ASP.NET Core Module stdout log. For accessing the Application Event Log you may use the Diagnose and solve problems blade in the Azure portal:

Sign in Azure portal> App Services >Select Diagnose and solve problems> Select Diagnostic Tools > Support Tools, select the Application Events button> Examine the latest error provided by the IIS AspNetCoreModule or IIS AspNetCoreModule V2 entry in the Source column.

You may also refer to Additional troubleshooting methods : https://docs.microsoft.com/en-us/aspnet/core/test/troubleshoot-azure-iis?view=aspnetcore-2.2#troubleshoot-on-azure-app-service

Let me know if issue persists

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BrandonMcAlees-7456 avatar image BrandonMcAlees-7456 ·

Thanks for your reply. I've enabled the stdout log and I have the result in my question. However, given the fact that none of my code changed, it can't be a code issue that's the problem. It also works fine locally and on S1 instances. It feels like to me that something must've changed on your F1 and D1 instances of an App Service.

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SnehaAgrawal-MSFT avatar image SnehaAgrawal-MSFT BrandonMcAlees-7456 ·

@BrandonMcAlees-7456 Thanks for replying! If you are still facing issue request you to send an email to AzCommunity[at]Microsoft[dot]com referencing this issue, we would like to work closer with you on this matter.

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