Halloween - The Final Chapter - S8-E5
Continuity mistake: Roseanne becomes pregnant at the beginning of Season 7, and it is before the Halloween and Thanksgiving episodes, so she is in her first trimester during the holidays. However, Roseanne does not give birth until the following year in the Season 8 Halloween episode. Her pregnancy has lasted for well over a year.
The Last Thursday in November - S8-E8
Other mistake: Roseanne gave birth to Jerry on October 31st. That Thanksgiving, on November 21st, Jerry was only 3 weeks old. However, he is side by side with Andy sitting in a high chair on his own, sitting straight up, holding his own head up.
Into That Good Night: Part 2 - S9-E24
Visible crew/equipment: When Bev hears "movement" on the baby monitor everyone rushes toward Roseanne on the stairs, and just as Roseanne comments that they're all "scary enough individually," we can see the second camera appear at the left side of the screen. Then, when Bev walks through the bedroom's doorway, there's movement of the boom mic at the top left corner of the screen, and when DJ turns on the camcorder the end of the set is visible from the POV of the camcorder.
Visible crew/equipment: When the Conners' friends come over and say "Hey Jailbird!" to Dan, a microphone can be seen coming down and going back up in the top left corner.
Revealing mistake: When Dan calls Becky, there is a shot of her and Mark in their Minneapolis apartment. This is the exact same set that is used later for Darlene's Chicago apartment when she goes to college. The fireplace shape and style, the wallpaper, position of the bathroom door, and the windows are exactly the same. The only difference is that the Darlene version looks shabbier.
Other mistake: The episode where Dan's dad visits and says he invented the rear windshield wiper he says Dan was 3 years old and Audrey was 8 months pregnant, but Dan's an only child.
Continuity mistake: After Booker announces the overtime, Roseanne asks Jackie for a quarter. Jackie takes her glove off her right hand. In the next shot, Jackie reaches into her purse and takes her glove off her right hand a second time, before getting a coin out of her coin purse.
Construction Junction - S8-E16
Continuity mistake: Stumbling in the dark bedroom, Dan rips off one of the bedposts, and he is holding it, while Roseanne turns on the light. Then, in the next shot, suddenly it's back on the bed again. (00:07:30)
Visible crew/equipment: While Darlene is at the jail to post bail for Dan, when she says, "I guess I should prepare you for all the things that have changed," the boom mic casts a shadow on the wall, at the right side of the screen. (00:04:25)
Continuity mistake: When Roseanne is talking on the phone to Jackie, she continually moves around the kitchen while preparing dinner. The extra-long phone cord goes from being completely wrapped around her waist to just being behind her, then wrapped around her again, without moving in a way that would unwind it.
Continuity mistake: Darlene and Becky's second-story bedroom window is on the side of the house and at the house's backside (D.J.'s room is at the front). However, when the girls argue and throw each other's items out the window, everything falls into the front yard, as viewed from the living room. Even if they threw stuff from the house's front, the roof extends too far out below two smaller upper windows. Everything would land on the roof.
Other mistake: After the crazy guy threatened Roseanne when she was working alone at the Lunch Box, Dan wanted to teach her and Jackie how to use a gun for protection. Dan seems to have forgotten that Jackie was a cop for the Lanford Police Force and already is trained in firearms use. He regularly saw her in uniform with a sidearm.
The Pied Piper of Lanford - S3-E25
Continuity mistake: In Ziggy's first appearance in the series (S2, EP. 16 "Born to Be Wild"), he says he has two kids. He states "I had to make mine. I checked them at birth, they're boys!" However in his second appearance in the series here, he states they were his girlfriend, Jill's, kids and the kids are back living with their father.
The Wedding - S8-E23
Character mistake: When Roseanne, Darlene, Jackie, Bev, Becky, and Nana Mary are dressing for Darlene's wedding, Nana Mary comments that all of them were pregnant when they married. However, Becky, was not pregnant when she and Mark eloped and they never had children together. Roseanne was not pregnant before marrying Dan. When the series began, Becky was 13 years old and Dan and Roseanne had been married 15 years.
Visible crew/equipment: In a scene where Darlene and Becky are in the kitchen, you can see the microphone above them for a couple of seconds.
Continuity mistake: When the girls are at the Lobo Jackie has a long scarf in her hair that moves between having the length of the scarf behind her back and then draped on her front left side.
Continuity mistake: Harris was born in 1997 (in season 9) so in 2018, that makes her 21 years old, but in the 2018 revival and its spinoff "The Conners", she is depicted as 17-18 years old and attending high school.
Canoga Time - S1-E11
Audio problem: When Dan and Roseanne start throwing things in the yard, you can hear it's not hitting grass or a porch, it's hitting a floor (from the set it was filmed on).
Continuity mistake: In the episode Terms of Estrangement Part 1, Roseanne goes for an interview at "The old Wellman Factory" which was closed down and turning into a printing press. Then, in the episode Lanford's Elite, Roseanne and Jackie team up with Edgar Wellman Jr. to try to save the factory from shutting down by paying off past due debts and making all the current employees part owners.