ASP.NET Core 2.0 Upgrade causes HTTP 502

ASP.NET Core 2.0 Upgrade causes HTTP 502

A lot of guys run into an error during the upgrade fom ASP.NET Core 1.x to ASP.NET Core 2.0:

HTTP Error 502.5 - Process Failure

The reason is very simple:

ASP.NET Core 2.0 merges all assemblies into one to improve the startup time. Side effect: your deployment packages has less files.

This also means: you have to configure your deployment and delete all additional files in your deployment target!

For example: by default this is not activated in the Visual Studio Team Services deployment tasks to Azure.

You have to activate this checkbox or configure your deployment to remove all additional / old files.