Anachronism:
In 1951, Nash drank a drink in a paper cup with a "recyclable" sign on it. This sign appeared much later than this time.
In John and Alicia’s room in Nash, the wall light switch is a modern design.
In the 1950s, Alicia used tapa household plastic film in the kitchen. In fact, it first appeared in the 1970s. In John Nash's neighbor's house, a family has a modern plastic phone booth outside.
In the 1950s, a plastic laundry basket can be seen in a scene.
Coherence:
Some pens were placed on Nash's desk, and they changed positions, first perpendicular to Nash, and then parallel.
When John said he might have to return to the hospital, he held her hand twice in two shots.
Display error:
The first scene was shot outdoors in Princeton in winter. The plot should have taken place in autumn. The CGI technology only added leaves to the trees, but the shadows of the trees did not see any leaves.
Factual error:
Alfred's name was spelled "Noble" incorrectly on the forum.
John Nash's son was born in 1959. The movie tells of them having children in the mid-1950s. In addition, in a scene in 1994, a female student about 18-20 years old poured tea. Nash said that he has a son at this age. In 1994 his son should be 35-40 years old.
