.NET Core app unable to start in IIS due to ErrorCode = '0x80004005 : 80008083

For now, there is a simple way to see what the actual error is. Open Console section from the App service, then try to run the dotnet app. From there we may get the full error message and trace info:

Error code: 0x80004005 means a file missing or can't be accessed.

Sub-code: 80008083 appears to be a version conflict.

This error means a different version of dotnet needs to be installed on the server.

As VS2017 RC is shipped with the new version of .NET Core SDK (.NET Core 1.0.4 SDK 1.0.1), you need to update framework on server as well.