General theory of relativity is made based on 4D Minkovski's spacetime, that is violates the basic principle of the modern astronomy (3D celestial sphere), and Einstein ignored the refraction of light.

This can be seen clearly in the Einstein's proving method of deflection of light by the Sun that isn't scientific and deeply wrong:

“Einstein proposed therefore, that photographs be taken of the stars immediately bordering the darkened face of the sun during an eclipse and compared with photographs of those same stars made at another time.” (LincolnBarnett, The Universe and Dr. Einstein, London, June 1949, Preface by Albert Einstein Himself, page 78).