How to make my nuget package compatibile with .net 4.5?

Question

I am trying to create a private nuget package to allow our organisation to share MVC models across mutliple apps. It's my first, and I was inspired by the Chris's answer to this question.

I thought I had it nailed.... it built OK and showed up in my local nuget feed with all the right metadata.

But when I tried to install the package in one of the apps, I get this error:

You are trying to install this package into a project that targets '.NETFramework,Version=v4.5', but the package does not contain any assembly references or content files that are compatible with that framework.

I thought the dependencies were compatible with 4.5. My 4.5 project (the target app) references the same versions of the dependencies.

I spotted one anomaly, which may (not) be relevant: In the project.json file, I have aspnet45 as the framework. But in solution explorer, the references shows a reference to ASP.NET 5.0.

---

Project.json

{
    "version": "1.0.0-*",
    "description": "My Shared Class Library",
    "authors": [ "MHL" ],
    "tags": [ "" ],
    "projectUrl": "",
    "licenseUrl": "",

    "dependencies": {
        "System.Collections": "4.0.0.0",
        "System.Linq": "4.0.0.0",
        "System.Threading": "4.0.0.0",
        "System.Runtime": "4.0.0.0",
        "Microsoft.CSharp": "4.0.0.0",
        "Microsoft.AspNet.Mvc": "5.2.2"
    },

    "frameworks": {
        "aspnet45": {
            "frameworkAssemblies": {
                "System.ComponentModel.DataAnnotations": "4.0.0.0",
                "System.Web": "4.0.0.0"
            }
        }
    }
}

---

Solution Explorer > References

---

Questions

1. Most importantly, how do I fix this and get it working?
2. How come I'm using aspnet45 in the project json, and the references section in Solution Explorer is showing ASP.NET 5.0?

3. What should I be putting in the dependencies, frameworks and frameworkAssemblies sections of the `project.json' file? In the code, the only using directives that I require are:

   using System;

   using System.Collections.Generic;

   using System.ComponentModel.DataAnnotations;

Q3 would probably be self-explanatory to a more competent developer. But I'm only just getting to grips with this, so any acompanying explanations / details would be welcomed.