Q:

Error 502.5 on my Azure Web app with dotnet core 2.0

I have a web application developed with Asp. Net Core 1.1 deployed on Azure and it works well.  I just migrated projects to use Asp. Net Core 2.0 and tried to deploy it on Azure.  The deployment went well, but when I open the site, I have a 502.5 error.  When I check my Azure log feed, I get the following error:

This error occurs when a CGI application does not return a valid set of HTTP headers, or when a proxy or gateway could not send the request to a parental gateway.  You may need to get a network trace or contact the proxy server administrator if this is not a CGI problem. 

Needless to say, it works well on my development machine with the same code.  
For more information, the way I migrated from 1.1 to 2.0 is to change the settings of the target structure to "netcoreapp2.0" and use the NuGet package "Microsoft. AspNetCore. All". 
When I use the web application console in azure and run: dotnet mywebapp.dll, I have the following error:

It was not possible to find a compatible frame version
  The specified 'Microsoft. NETCore. App' frame, version '2.0.0' was not found. 
  - Check the application's dependencies and target a version of the framework installed at:
  \
  - Alternatively, install the version of the '2.0.0'

Dotnet --version:
2.0.0-preview2-006497
my csproj target the good framework:
  <PropertyGroup>
    <TargetFramework>netcoreapp2.0</TargetFramework>
  <PropertyGroup>

I also removed content of site\wwwroot and redeploy, but no change. 
What is wrong ?  

A:

In local, I run : Update-Package -reinstall
One package was update in one project. 
Then I deploy again and everything is ok

