The Origin of the Fantastic Four: Part 1 - S1-E1
Other mistake: When Puppet Master is making a clay figurine of Thing, the mold he uses doesn't have a Thing-shaped interior with which to make a detailed figurine. The figurine should have just looked like an undefined human-shaped figure. (00:15:20)
The Origin of the Fantastic Four: Part 1 - S1-E1
Plot hole: The beginning of the episode shows video footage for Dick Clark's telethon of the Fantastic Four battling Namor underwater. However, the Fantastic Four didn't even meet Namor until the third episode of the series. (00:01:00 - 00:02:02)
The Origin of the Fantastic Four: Part 1 - S1-E1
Continuity mistake: When Thing first walks into Puppet Master's house, the doors are gray. When the shot changes, the doors are blue. (00:17:00)
The Origin of the Fantastic Four: Part 1 - S1-E1
Continuity mistake: When Johnny slouches down on the couch, the black 4 on a white circle on the chest of his uniform suddenly becomes a white 4 on a black circle. (00:16:33)
The Origin of the Fantastic Four: Part 1 - S1-E1
Continuity mistake: When Puppet Master is putting the Thing figurine inside the dollhouse, the windows on the bottom level are smaller than his hands. When the shot changes, he's suddenly able to fit his entire head and right shoulder through one of the windows. (00:15:41)
The Origin of the Fantastic Four: Part 1 - S1-E1
Continuity mistake: When Dick Clark walks back over to his desk after giving instructions to the camera operators, Sue is shown sitting equidistant between Johnny and Reed. When the shot changes, she is suddenly sitting closer to Reed, and Johnny is nowhere to be seen. Reed also suddenly has blonde hair. (00:15:03)
The Origin of the Fantastic Four: Part 1 - S1-E1
Audio problem: When Puppet Master is saying "I can see perfectly," his mouth movement is not in sync with the dialogue.
The Origin of the Fantastic Four: Part 1 - S1-E1
Audio problem: When Johnny is saying "I can fly! Whoa, ha ha," his mouth isn't moving.
The Origin of the Fantastic Four: Part 1 - S1-E1
Continuity mistake: When Sue turns invisible for the first time, Ben Grimm's hair alternates between being gray and auburn. (00:07:46 - 00:09:08)
The Origin of the Fantastic Four: Part 1 - S1-E1
Audio problem: When Thing is saying "Pick it up, Reed. You were saying how we survived the crash," his mouth movement is not in sync with the dialogue.
The Origin of the Fantastic Four: Part 1 - S1-E1
Audio problem: When Reed is saying "While we failed to unlock the secret of the streaking phenomenon," his mouth movement is not in sync with the dialogue.
The Origin of the Fantastic Four: Part 1 - S1-E1
Audio problem: When Sue is saying "Reed, Johnny's on fire," her mouth is closed for the word "fire."
The Origin of the Fantastic Four: Part 1 - S1-E1
Continuity mistake: When the Fantastic Four are first shown on Dick Clark's show, Johnny is seated on Sue's right and Reed is seated to her left. A couple of shots later when Dick Clark is telling them what his telethon viewers really want to know, Johnny and Reed have swapped sides. (00:02:06)
The Origin of the Fantastic Four: Part 1 - S1-E1
Continuity mistake: When Sue is holding up the book for Dick Clark, her right hand is on the bottom of the book on the spine side, and her left hand is in the upper right corner. When the shot changes, her right hand is suddenly closer to the top-left corner. (00:02:18)
The Origin of the Fantastic Four: Part 1 - S1-E1
Factual error: After the group has crash-landed back on Earth and Sue is saying "We're all alive," the moon behind everyone is far too large. (00:06:34)
The Origin of the Fantastic Four: Part 1 - S1-E1
Continuity mistake: When the shuttle crash-lands back on Earth, it is twilight. When the group exits the shuttle, it is suddenly dark outside.
Suggested correction: There's no way of knowing how long they were in the shuttle after it crashed, what happened to them, or what they might have been doing. It seems it's just meant to show a passage of time.