Unable to load application or execute command

Always got error:

k web
Unable to load application or execute command 'Microsoft.AspNet.Hosting'. Availa
ble commands: run, web.

Can you help?

Thx!
-William

details:

d:\study3\vnext\WheresLouSamples\04.Owin>go

    kvm upgrade
Determining latest version
KRE-svr50-x86.1.0.0-alpha4-10353 already installed.
Cannot find KRE-svr50-x86.1.0.0-alpha4-10353, do you need to run 'kvm install 1.
0.0-alpha4-10353'?
Setting alias 'default' to 'KRE-svr50-x86.1.0.0-alpha4-10353'

    kpm restore --source https://www.myget.org/F/aspnetvnext
Restoring packages for d:\study3\vnext\WheresLouSamples\04.Owin\project.json
Attempting to resolve dependency 04.Owin >= 1.0.0
Attempting to resolve dependency Kestrel >= 1.0.0
Attempting to resolve dependency Microsoft.AspNet.Server.WebListener >= 1.0.0
Attempting to resolve dependency Microsoft.AspNet.Owin >= 1.0.0
Attempting to resolve dependency mscorlib >=
Attempting to resolve dependency System >=
Attempting to resolve dependency System.Core >=
Attempting to resolve dependency Microsoft.CSharp >=
Resolving complete, 6777ms elapsed
Installing Microsoft.AspNet.Owin 1.0.0-alpha4-10335
Restore complete, 6886ms elapsed

    k web
Unable to load application or execute command 'Microsoft.AspNet.Hosting'. Availa
ble commands: run, web.