The Divine Simplicity of God
As you are probably aware, confessions such as the WCF and the 1689 LBCF talk about the Divine Simplicity of God. Both agreeing.

In the WCF 2.1 in particular it says.
I. There is but one only, living, and true God, who is infinite in being and perfection, a most pure spirit, invisible, without body, parts, or passions; immutable, immense, eternal, incomprehensible, almighty, most wise, most holy, most free, most absolute; working all things according to the counsel of his own immutable and most righteous will, for his own glory; most loving, gracious, merciful, long-suffering, abundant in goodness and truth, forgiving iniquity, transgression, and sin; the rewarder of them that diligently seek him; and withal, most just, and terrible in his judgments, hating all sin, and who will by no means clear the guilty."

I had never really thought that people who held to these confessions would have a problem with them until James White vehemently came out against this doctrine.

The controversy seemed to happen when James E. Doleza wrote a book about the doctrine from WCF 2.1.
James White in his Dividing Line broadcast spoke against this particular doctrine agreeing with William Lain Craig.
First of all, I was a little surprised that White would agree with Craig; over the 1689 LBCF; because it is a rarity that he agreed with Craig on anything.
As I was listening to White on the Dividing Line Broadcast, after a while I turned it off because what he said; although passionate, I was no closer to understanding his disagreement. I was not even certain it was a big deal.
The only real thing I understood from James White is (agreeing with Craig) that the Classical Reformed understanding makes no sense. Apparently, Charles Hodge is another theologian that had a problem with the Classical Reformed view.

Can anyone shed any light on that subject, as I am trying to understand where James White is coming from and whether it is a big deal?

I will say that in the last year or so, James White has been vehemently standing against 1689 Federalism; which is the view of the 1689 LBCF held by the writers of the confession; as seen in the writings of Nehemiah Coxe (and others) who is believed to be the editor of the 1689 LBCF.

James White of course, says he holds to the 1689 LBCF, but his understanding of the confession is different than what is commonly called 1689 Federalism; In fact vehemently so.