http://www.mqup.ca/space--time-and-e...0773524729.php
J.B. Kennedy, Space, Time and Einstein: An Introduction, p. 189: "Even though general relativity predicts black holes, Einstein always denied their existence."

General relativity is an empirical model - it can predict anything. So it can predict both existence and non-existence of black holes. Einstein preferred "non-existence" but LIGO folks disagree. Тhey know general relativity even predicts important features of black holes - LIGO folks were somehow able to extract those features from gravitational waves.

https://www.quantamagazine.org/20160...ick-interview/
""There are no gravitational waves ... " ... "Plane gravitational waves, traveling along the positive X-axis, can therefore be found ... " ... " ... gravitational waves do not exist ... " ... "Do gravitational waves exist?" .... "It turns out that rigorous solutions exist ... " These are the words of Albert Einstein. For 20 years he equivocated about gravitational waves, unsure whether these undulations in the fabric of space and time were predicted or ruled out by his revolutionary 1915 theory of general relativity. For all the theory's conceptual elegance -- it revealed gravity to be the effect of curves in "space-time" -- its mathematics was enormously complex."

Einstein equivocated but LIGO folks don't. According to them, general relativity not only predicts the existence of gravitational waves - it even gives minute detail about them. And the detailed predictions were gloriously confirmed, LIGO folks honestly and proudly say.

Pentcho Valev