In keeping with the original series run's practice of reusing Canadian character actors in multiple unrelated parts, Hiro Kanagawa, Christine Willes, and Alex Diakun each appeared in one of the three first episodes of the long-delayed tenth season aired in 2016. Kanagawa played two different characters in the second and fourth seasons; Wiles had the small but recurring role of F.B.I. Agent Karen E. Kosseff (Scully's therapist) in three different episodes; and Diakun played four different characters in the second and third seasons and the second movie.
The Truth is out there, Mulder. But so are lies.
In many episodes it is clear that the agents are not in the region of the country or the world, described in the captions or the script. This especially becomes evident when the series began filming in Southern California and the vegetation and the terrain clearly could have only been that region.
Occasionally, the phrase "The Truth Is Out There" in the opening credits has been changed to something else, for example "Trust No One" or "Apology is Policy".
The 'previously on The X Files' segments are missing from the DVD Season boxset releases.