Factual error: Aphrodite's son and Psyche's husband is Eros, not Cupid. Venus's son is Cupid. (Eros is Greek and Cupid is Roman).
Continuity mistake: In the first episode Xena calls her horse Argo a boy, then later in the series he becomes a she.
Other mistake: Across the show Xena's past relationship with Ares is unclear. In "The Reckoning" (Season 1), Xena says to Ares that she used to wonder what he looked like - implying that they had never met face to face. Yet in "Succession" (Season 5), Xena asks Ares if this portal world is just to watch his new girlfriend fight and he responds, saying it is to watch his old girlfriend (Xena) fight. If they had been in a relationship, surely a: Xena and Ares would have met face to face and therefore b: Xena would know what Ares looked like.
Continuity mistake: In the episode 'The Xena Scrolls,' the chakram that is buried in Ares' tomb is the chakram from the first four seasons. However, as the chakram is neutralised in the episode 'Chakram' and is given back to the cloned Xena in the episode 'The Clones', how could the chakram be neutralised before Xena dies, be separated in the 1940s when they discover the Chakram in Ares' tomb and then be neutralised in the episode with the clones?
Other mistake: Xena travels to the land of the Norse gods in 'The Rhinegold', 'The Ring', 'The Return of the Valkyrie.' Brunhilda says that Xena came from a distant land in the east, meaning that she travelled from Chin or Japa (most likely), not Greece. When would she have done this, and why is Borias not with her, etc.?
Other mistake: If Lyceus is killed 11 years ago (the second year Xena and Gabrielle travel together - 2x02) and Solan is born roughly 8 years ago (the same night Borias is killed), then in about two years, Lyceus is killed, Xena gets an army, Caesar betrays Xena, Xena meets Borias (and gets him to leave his son), they go to Chin and meet Lao Ma, Xena gets pregnant and meets the Amazons/Alti, Borias dies and Solan is born. No way does this all fit into a few years. And what happened after Solan was born?