Why the COM Client cannot activate the COM server generated by hosting code

Last night, I was so tired that I was so bored that I was always confused when I got the result for three or more nights: I was unable to create objects by calling C # exported class libraries using vc6, And I used VB to do the same. Re-examine the interface definition and consciously regulate it. How can this problem be solved?
Looking at the framework design guide, I suddenly found the following sentence:

If there is no common default constructor (constructor without parameters), the COM Client cannot create this type.

God!

 I have no default structure! Standards are standards.

Wrong. It's still not that simple, or the error of not finding the object is reported, depressing! Is it because my C # component references too many other managed dynamic libraries ?...