ASP.Net Core Application process failed to start due to Anti-virus scanning

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.