Contradiction with Matthew 16:20
Jesus instructed his disciples to tell no one that he was the Christ, while in John 20:16, Jesus reveals Himself openly to Mary by calling her name.
Matthew 16:20: Then charged he his disciples that they should tell no man that he was Jesus the Christ.
Contradiction with Mark 9:9
Jesus commands the disciples to keep His transfiguration secret until His resurrection, contrasting with John 20:16 where He is revealed to Mary immediately after resurrection.
Mark 9:9: And as they came down from the mountain, he charged them that they should tell no man what things they had seen, till the Son of man were risen from the dead.
Contradiction with Luke 24:16
The disciples' eyes were kept from recognizing Jesus, which contrasts with Mary instantly recognizing Jesus in John 20:16.
Luke 24:16: But their eyes were holden that they should not know him.
Contradiction with John 16:25
Jesus speaks of using figures of speech and not plainly, which contrasts with His clear revelation to Mary in John 20:16.
John 16:25: These things have I spoken unto you in proverbs: but the time cometh, when I shall no more speak unto you in proverbs, but I shall shew you plainly of the Father. [proverbs: or, parables]
Contradiction with Mark 16:11
When Mary Magdalene tells others Jesus is alive, they do not believe her, which contrasts with her immediate recognition and acceptance of Jesus in John 20:16.
Mark 16:11: And they, when they had heard that he was alive, and had been seen of her, believed not.