问题
I installed the KVM using command line and my web project in VS2015 preview broke not compiling, but if add a new web project all works fine, how do uninstall the KVM so I can get my old project working. In this video Scott mention the issue but no solution, please see link, the video mention the issue at the 8:00 minute video
1: http://channel9.msdn.com/Series/Whats-New-with-ASPNET-5/05 I change the to use the default alias but that did not work
NuGet Settings
回答1:
I believe your versions are out of sync. Check your project.json and make sure you are not using different versions. I found that when I had 1 dependency that used 3.0.0-* it upgraded to beta2 from beta1. All of my other dependencies had beta1 actually defined. (Ex: 1.0.0-beta1). If the beta2 assembly shares the same dependency as one of your assemblies using beta1 it will override the older version of the shared assembly that is being used and causes your older version to fail.
回答2:
You can remove any KRE package by deleting it from c:\Users\<user>\.kre\packages\. If you want to remove KRE and KVM then remove both the .kre folder completely.
However, you don't have to remove it to use a different version. You can either use kvm use <version> or, from VS, select the target framework in the project properties.
回答3:
I have similar issue and I solved it by following steps.
In NUget Package Manager I selected only one nuget.org ( Disable myget.org by unselecting it)
I goto C:\Users\<>.kre\alias directory. Here you will find default.txt and I replace default.txt value with KRE-CLR-x86.1.0.0-beta1 ( If you downloaded latest version of Kre then this file change and it create problem for VS 2015 Preview)
After this close your solution and open it again. If possible then open as Administrator.
I hope this works for you as well.
来源：https://stackoverflow.com/questions/27953179/installing-kvm-broke-current-asp-net-vnext-web-project