default construction is disabled for type

[Machine Code via Digitalmars-d-learn]

What's that error? below code used to work fine, now it gives 
this compiler error.

class Keyword
{
        this(string value, Token type)
        {
                this.value = value;
                this.type = type;
        }
        string value;
        Token type;
        Keyword next;
}


static Keyword[] hashtab = new Keyword[hashtab_siz];