This post has been republished via RSS; it originally appeared at: IIS Support Blog articles.
When you host ASP.Net Core 2.x version in IIS/IIS Express, the application runs in a process separate from the IIS worker process (out-of-process) with the Kestrel server. Here you can find the detailed explanation on publishing an ASP.NET Core app to an IIS server.
Recently, I came across an issue where ASP.Net Core 2.x version failed to start with the error below:
Exceptions:
After browsing the page, the exception on the browser:
HTTP Error 502.5 - Process Failure
Common causes of this issue:
The application process failed to start
The application process started but then stopped
The application process started but failed to listen on the configured port
Troubleshooting steps:
Check the system event log for error messages
Enable logging the application process' stdout messages
Attach a debugger to the application process and inspect
In the Event Viewer logs, the error will be:
Event ID 1020 from Source: AspNetCoreModuleV2
Application '/LM/W3SVC/1/ROOT/Site' with physical root '<path>' failed to start process with commandline '<path><application>.exe ' at stage 'CreateProcessW', ErrorCode = '0x80070002', assigned port xxx, retryCounter '0'.
Root Cause:
There are many reasons when process fails to start. One of the reasons is documented here:
ASP.Net core application exe was quarantined by the Anti-virus.
Resolution:
The application runs in a process separate from the IIS worker process (out-of-process). So two processes will spawn to process the requests: IIS worker process(w3wp.exe) and Application process(dotnet.exe/Application.exe)
Both w3wp.exe and exe of the application(application.exe or dotnet.exe) must be excluded from Anti-virus scanning.
This article includes information about folders that need to be excluded from antivirus scanning in ASP.net applications.