Factual error: Mulder refers to a Royal Navy vessel that sailed from Leeds. No large ship can sail from there - it is at least 50 miles from the coast.
Factual error: The originally-aired version spelled the word "Acquisition" without the "c" and it appeared in the credits as "Aquisition." This goof has been corrected in the DVD versions.
Return of the Green Ranger (2) - S2-E45
Factual error: Billy, Kim, Rocky, Aisha, and Adam return to Angel Grove in the 1700's...and there are British Redcoats there. On the West coast, in California. England never deployed troops to California, especially considering it was part of the empire of Spain at that time.