Steps to reproduce:
1. Choose 'Extract superclass' refactoring to SomeClass from following code:

public class SomeClass<T>
{
    private const float someConst = 0.5f;
    public float MyAAA()
    {
        return someConst;
    }
    public SomeClass(T items)
    {
    }
}

Corresponding dialog appears.
2. Select someConst in this dialog and press Next button.
Wrong result: there is error in code:

public class SomeClassBase<T>
{
    protected const float someConst = 0.5f;
}

public class SomeClass<T> : SomeClassBase<T>
{
    public float MyAAA()
    {
        return SomeClassBase.someConst;
    }
    public SomeClass(T items)
    {
    }
}

It should be:

...
public class SomeClass<T> : SomeClassBase<T>
{
    public float MyAAA()
    {
        return SomeClassBase<T>.someConst;
    }
    public SomeClass(T items)
    {
    }
}

or

...
public class SomeClass<T> : SomeClassBase<T>
{
    public float MyAAA()
    {
        return someConst;
    }
    public SomeClass(T items)
    {
    }
}