The front end on Lincoln Town Car limousine used to transport Hervé and Daniel is switched between 1990-1994 and 1995-1997 (narrower height and one-piece clear lens).
Camille did "Fantasy Island" after she married Hervé, not before; in the two episodes she was in, she is credited as Camille Villechaize.
In his office, Marty has Tattoo backpacks and lunch boxes. Tattoo backpacks and lunch boxes were not part of the official "Fantasy Island" merchandise.
Peter is watching a 1987 Newlywed Game episode in 1993 in his hotel room. No network/station was airing the series at that point.
It may seem like a plot hole that Hervé can't afford to pay for dinner, yet he throws wads of cash at the strippers, and is driven around town in a chauffeured limousine. However, at the time of his death, it is estimated that Hervé Villechaize had a net worth of over $100 thousand. Given Hervé's colorful behavior, it is not out of the question that he would have had an unpaid credit card or exceeded his limit, but would have plenty of cash.
"Bittersweet Symphony" plays as Danny quits his job at the end of the movie. It may seem like a goof, since the scene is set in 1993 and the song was released in 1997, but it's actually not. The song does not play as within the story; it plays as a soundtrack over the end scene. Thus, there is no conflict within the events of the film.
Hervé chases Camille in the front yard as she runs into the house. We then see him on a horse as he fires a gun into the air. This appears to be a goof, as it's never explained where the horse came from or how Hervé got onto it. However, it's really just sloppy editing. It's implied that there is a bit of a time jump here of a few minutes or longer. During which time, Herve got a horse from the 1.5 acre ranch that he and Camille lived on, which was known to have numerous animals, including horses.
In the newspaper with the divorce article that Ricardo Montalban reads, the article in the column to the left of it has a lot of repeating text.
The song "Everything Zen" by English rock band Bush is featured in the strip club scene that takes place in August 1993. The song first appeared on their debut album "Sixteen Stone", which was released in December 1994, and was not released as a single until late January 1995.
When they are in the strip club, Hervé gives several $20 & $10 bills to the strippers. There bills are clearly the newer-style with a larger face on the front. The events of the film take place in 1993, but these bills were not released until 1996 & 2000, respectively.
Nearly every military uniform worn in the film has mistakes that should have been caught by the wardrobe staff or by the film's technical advisor. Examples are, ribbon out of order or not correct for the character or time period, uniforms with a mixture of enlisted and officer insignia attached, insignia located in incorrect locations, and too many more to mention.
The CRT television in Herve's hotel room (flat glass front style) would not have been widely used or even available in 1993. This style of television set didn't become widely used until the late 90s and certainly wouldn't be used in a hotel room setting.
Montalbán is depicted as having a much-bigger role in the production of "Fantasy Island" than he actually did.