It is not that Einstein's theory is not correct because it is.
One of the premises is however wrong.
Neither Einstein nor anybody else in those days suspected that time (as we generally think about it) does not exist.
However as J.M.E. McTaggart showed back in 1908 when he published hit proof of the unreality of time, that is actually the case.
McTaggart used logic I found out by trying to understand time and motion.
Have a look at where I am trying to explain how it could work.