You really should stop relying on wiki. You are looking at the pseudo stress-energy of the gravitational field concerning gravitational waves as I guessed. It shouldn't give you doubts in relativity, just in your source description. Dirac didn't save anything. It wasn't until the Noether theorem that it was understood just what was conserved in general relativity that corresponded to Newtonian energy and momentum in appropriate limits. In fact that finding of Dirac's is what causes not solves concern for how such things are conserved in general relativity.

Where it comes to gravitational radiation it obeys the exact same real tensor law as all matter does in general relativity, Einstein's field equations. What they were having trouble understanding prior to Noether is how conservation worked specifically because of the nonlinear nature of Einstein's field equations. The real stress energy tensor for gravitational radiation or waves is zero. However because of the nonlinearity, the Einstein tensor and the stress energy tensor can be thought of as a sum of expanded terms where the first order corresponds to a Newtonian potential, and stress energy acting as the source term for inhomogeneous linear wave equations now days referred to as GEM and the higher order terms of the sum would correspond to the nonlinear aspect of the Einstein tensor's expansion. The sum total of the stress-energy tensor for gravitation alone would be zero, but the first order term of its expansion would not be and is this pseudo-tensor your concerned with. So the problem for conservation was that gravitational radiation would in the Newtonian limit act as a source term and exchange energy any momentum with test particles. But how could it exchange energy and momentum with test particles if its real stress energy tensor sums to zero? You see, his pseudo-stress-energy of gravitation poses the problem for conservation. It doesn't solve it.
In history what was once defined as energy has often been revised or expanded in order to retain the concept of energy conservation. For example things in motion under friction loose energy. So the definition of energy was expanded to include heat so that energy could be conserved if one accounted for the heat. Newtonian energy any momentum is not conserved in general relativity because of exchanges with that pseudo-stress-energy of gravitational radiation. Noether was the one that found out how conservation laws work for general relativity. She found that what energy and momentum parameters are conserved in general relativity are actually what corresponds to isometries in the spacetime geometry. In the end, all things gravitational waves with a real but zero stress energy tensor, or matter with a nonzero real stress-energy tensor, whatever, obey Einstein's real tensor law of gravitation, his field equations, and what is conserved in general relativity is NOT Newtonian energy and momentum, but rather energy and momentum parameters that correspond to spacetime isometries.