Long after Einstein’s death, Shapiro sent a radar signal to Venus, in its position opposite of the sun, and half an hour later received it back. With this astonishing experiment he proved part of the delay (190 microsec) was caused by the gravitation of the sun.

Eddington, expert in Einstein’s theory of General Relativity, tried earlier to calculate such an outcome using the Schwarzschild solution. He only questionably changed a suffix.

This article  explains Eddington’s ‘blamage’ and show that he missed a chance to do it correctly.
The authors show that Shapiro went another way, using directly the influence of two elements of Einstein’s covariant metric tensor.

As a next step, the authors proudly repair the Schwarzschild solution in three aspects.
Now a merger of the Schwarzschild solution and the Special Relativity is obtained!
Also, due to the essential Noether reference frame, the speed of light remains invariant in all directions as well as other Nature constants and it now explains both the Shapiro- and the Hafele-Keating experiment.

With this repaired S-solution we can explain the core temperature of the sun and the shape and size of static black holes: surprisingly their radius is always 1.5 times higher than their Schwarzschild radius!

So there exists no ‘event horizon’.