BTC BTC - 4 months ago 36
C# Question

.Net MVC 4 Project fails with Event Log Error "The Module DLL C:\WINDOWS\system32\inetsrv\aspnetcore.dll failed to load. The data is the error."

This is not a DotNetCore project (it's an MVC 4 project) and the app pool is properly configured to use dotnet CLR v4, yet after updating to a new version of Windows 10 (be it an insider build, or the new Anniversary Update), starting the app fails and the event log shows the following error:

The Module DLL C:\WINDOWS\system32\inetsrv\aspnetcore.dll failed to load. The data is the error.

I don't have any need for aspnetcore.dll yet. And removing references to the DLL for the site in IIS doesn't solve the problem. Any Tips?

BTC BTC
Answer

Easiest Solution:

  1. Search Cortana for Programs and Features to open the legacy Control Panel's installed applications list.
  2. Find and click the entry for Microsfot .NET Core 1.0.0 - VS 2015 Tooling ...
    • My version is "Preview 2"... though if they don't fix this, you may have a newer version
  3. Click Change.
  4. Click Repair.

The source of this problem seems to be the build upgrade process for Windows 10, where it re-installs IIS... while it copies over all the site settings to the new applicationHost.config, it seems to break any non-standard modules you previously had installed. For example, this same problem also affects the URL Rewrite 2 module (which is also fixed by running a repair).

Hopefully the team at Microsoft who works on maintaining the IIS config between build updates will get a chance to fix this. Until then, you have to do this repair after installing any new Windows builds.