FileLoadException: Could not load file or assembly System.Runtime, Version=4.2.0.0
This can happen if you create an ASP.NET Core 2.0 Web Application that targets the [.NET Core]
platform, deploy to Azure (or deploy locally), and then change it to target the [.NET Framework]
instead.
e.g. if you change
<PropertyGroup>
<TargetFramework>netcoreapp2.0</TargetFramework>
</PropertyGroup>
to
<PropertyGroup>
<TargetFramework>net461</TargetFramework>
</PropertyGroup>
but if you do not delete the existing files from Azure before redeploying you will get this error.
It can also happen in the following scenario:
First create a .NET Core project with Visual Studio 2017 with:
File -> New Project -> Visual C# > Web > Asp.NET Core Application`
Choose the
[.NET Core]
Platform on the Second Screen.
- Deploy the web app to Azure.
Then create a new Project with :
File -> New Project -> Visual C# > Web > Asp.NET Core Application`
Choose the .NET Framework setting on the Second Screen.
Redeploy without deleting the existing files from Azure will cause this error.
Hope that helps.
What worked for me was:
Simply, empty the bin folder in your project and rebuild. I had to manually delete the contents via windows explorer as 'clean' left files kicking around.
Job done.