If gravitational waves have been found, where did the missing solar masses go?

Amazing Grace. But I'm a bit worried about an author who writes "Einstein’s famous Theory of General Relativity turned our understanding of space and time on its head. He argued that neither is fixed. Instead, they are dependent upon each other — and the state of one changes with the condition of the other."

It's the general theory of relativity, not the theory of general relativity. It's the theory that was generalized by removing the non-acceleration constraint; so the general theory is more general and comprehensive than the special theory of relativity.

As to the missing masses, remember mass.energy equivalence. And remember that mass, energy, and stress are all sources of warped space (aka, gravity) according to the GTOR. So the radiated gravity as energy might very well be where those three missing solar masses went to. It's like an EM transmitter; it takes energy to radiate that radio energy.

But we'll learn more soon.