Einstein introduced General Relativity 2.0 I stumbled upon the following article: https://www.livescience.com/einstein-biggest-failure-teleparallel-gravity.html . The following quote is taken from the mentioned article.

In his attempts to make a super-theory of everything, Einstein
introduced General Relativity 2.0. The basic version of relativity
only cares about space-time's curvature. But Einstein's reboot also
paid attention to space-time's twistiness, or torsion. There was no
need to include torsion in his original theory, because it turned out
that all you needed was curvature to explain gravity. But now that
Einstein was trying to explain more than gravity, he had to include
additional effects.

When did Einstein come up with this second version, i.e 2.0, of the general theory of relativity?
Was NASA's Gravity Probe B experiment more about the General Relativity 2.0 than about General Relativity 1.0 since it was more about measuring the twistiness of space-time?
 A: From https://en.wikipedia.org/wiki/Teleparallelism

Teleparallelism (also called teleparallel gravity), was an attempt by Albert Einstein[1] to base a unified theory of electromagnetism and gravity on the mathematical structure of distant parallelism, also referred to as absolute or teleparallelism. In this theory, a spacetime is characterized by a curvature-free linear connection in conjunction with a metric tensor field, both defined in terms of a dynamical tetrad field.


[1] Einstein, Albert (1928). "Riemann-Geometrie mit Aufrechterhaltung des Begriffes des Fernparallelismus". Preussische Akademie der Wissenschaften, Phys.-math. Klasse, Sitzungsberichte. 1928: 217–221.

Here's an electronic version of Einstein's paper
https://echo.mpiwg-berlin.mpg.de/ECHOdocuView?url=/permanent/echo/einstein/sitzungsberichte/B8AG2G5E/index.meta
which was translated in 
https://arxiv.org/abs/physics/0503046v1 
Translation of Einstein's Attempt of a Unified Field Theory with Teleparallelism 
Alexander Unzicker, Timothy Case 
(see the second paper, starting on pg.6)
Here's another article on it
https://arxiv.org/abs/physics/0405142v1 
Field equations in teleparallel spacetime: Einstein's Fernparallelismus approach towards unified field theory
Tilman Sauer
Historia Math. 33 (2006) 399-439
10.1016/j.hm.2005.11.005

A historical account of Einstein's 'Fernparallelismus' approach towards a unified field theory of gravitation and electromagnetism is given. In this theory, a space-time characterized by a curvature-free connection in conjunction with a metric tensor field, both defined in terms of a dynamical tetrad field, is investigated. The approach was pursued by Einstein in a number of publications that appeared in the period from summer 1928 until spring 1931. In the historical analysis special attention is given to the question of how Einstein tried to find field equations for the tetrads. We claim that it was the failure to find and justify a uniquely determined set of acceptable field equations which eventually led to Einstein's abandoning of this approach. We comment on some historical and systematic similarities between the 'Fernparallelismus' episode and the 'Entwurf' theory, i.e. the precursor theory of general relativity pursued by Einstein in the years 1912-1915.

(I haven't read any of them.
I was just curious to see what this is about.
So, I did a Google search.)
