Patrick's Coupon/Out of the Picture - S10-E10
Audio problem: In "Out of the Picture", Larry is holding a fork in his hand when Squidward shows him his painting. In the next shot, Larry raises his claw and the fork is no where to be seen and no sound of it clattering is heard.
The Fish Bowl/Married to Money - S9-E18
Continuity mistake: In "The Fish Bowl", Sandy has a wristwatch on her right wrist when she first appears on the bus. When she sits near the front to observe the fish, the wristwatch has disappeared and doesn't reappear.
The Fish Bowl/Married to Money - S9-E18
Audio problem: In "The Fish Bowl", after Patrick takes the bowls of ice cream and eats them both, he throws them behind him. The bowls just disappear in mid air without leaving the frame (also an "other mistake") but the sound of the ceramic bowls breaking is still heard.
The Fish Bowl/Married to Money - S9-E18
Continuity mistake: In "Married to Money", Pearl cries and her tears flood Mr. Krabs' house. When this happens, he pulls a in the floor to let the water drain. In a few shots, this plug and drain are missing.
Hooky / Mermaid Man and Barnacle Boy II - S1-E20
Continuity mistake: In "Hooky", Spongebob is being pulled by the hook and grabs onto a flower to try and hold onto it and it becomes limp. In the next shot, this limp flower he just grabbed has vanished.
Krabby Land / The Camping Episode - S3-E19
Other mistake: In "Krabby Land", Mr. Krabs as "Krabby The Clown" finishes his short speech and goes into his office. When he slams the door, bubbles float up and those bubbles stay motionless in the air for a few frames.
Krabby Land / The Camping Episode - S3-E19
Continuity mistake: In "The Camping Episode", Squidward sets down a blanket to lay under the stars and in a couple of shots, the blanket disappears.
Krabby Land / The Camping Episode - S3-E19
Continuity mistake: In "Krabby Land", Spongebob goes to check his motivational quote and from far away, the page is flipped up. But in the next shot, it is a close up and the page is flat against the stack. In the following shot, the page is flipped up again.
Pizza Delivery / Home Sweet Pineapple - S1-E5
Continuity mistake: In "Home Sweet Pineapple", Spongebob goes into Squidward's house to spend the night and sits in his bed with the pillow just the right size for him. But in the next shot, when Squidward climbs into bed next to him, the pillow has drastically grown and now both of them can lay on it perfectly.
Jellyfishing / Plankton! - S1-E3
Continuity mistake: In "Jellyfishing", Patrick and Spongebob slide down two ropes and burn their hands on them. The two shots after they land show them trying to cool down their hands and in the shot after that, the ropes they had just slid down on have disappeared.
Pizza Delivery / Home Sweet Pineapple - S1-E5
Continuity mistake: In "Pizza Delivery", Spongebob points out the antennae for the boat during his vehicle inspection, but in a few shots, when he's checking the tire pressure, the antennae has vanished.
Born Again Krabs (aka A Penny Saved) / Safety Freak (aka I Had An Accident) - S3-E17
Continuity mistake: In "I Had An Accident", Sandy opens the door to show that she was being "attacked" by a gorilla and Spongebob is looking through that door to see the events unfold. But after a couple of shots, the door has closed by itself and Spongebob has to open it again before going outside.
SB-129 / Karate Choppers - S1-E14
Continuity mistake: In "SB-129", every time Squidward goes to answer the door to find Spongebob and Patrick there, the picture on the wall next to the door changes noticeably.
Born Again Krabs (aka A Penny Saved) / Safety Freak (aka I Had An Accident) - S3-E17
Continuity mistake: In "Born Again Krabs", when Mr. Krabs first makes his appearance next to Davy Jones' locker, there is some coral taking up a part of the bottom left corner. In a few shots, that same set of coral has disappeared.
Born Again Krabs (aka A Penny Saved) / Safety Freak (aka I Had An Accident) - S3-E17
Continuity mistake: In "Born Again Krabs", after Mr. Krabs returns from the hospital and the Krusty Krab has their "Grand Re-Opening", there are two big yellow signs on the front windows, but in the next shot from the inside, these signs have vanished.
Procrastination / I'm With Stupid - S2-E19
Continuity mistake: In 'Procrastination' when SpongeBob takes the stack of paper out of the drawer, the paper is the only thing in the drawer. In the next shot, SpongeBob pulls a pencil out of the drawer.
The Graveyard Shift / Krusty Love - S3-E13
Continuity mistake: In 'The Graveyard Shift' Squidward explains that there are three signs concerning the arrival of the Hash-Slinging Slasher. He then holds up three hands. In the next shot, he is only holding up one hand.
Sold!/Lame and Fortune - S9-E21
Continuity mistake: In 'Lame and Fortune', a big box of fortune cookies drops in SpongeBob's backyard. When Gary goes to read his fortune, he leaves a slime trail. However, the slime trail disappears and reappears between shots.
Born Again Krabs (aka A Penny Saved) / Safety Freak (aka I Had An Accident) - S3-E17
Continuity mistake: In "Born Again Krabs", the doctor taking care of Mr. Krabs drops his clipboard and runs. When the Flying Dutchman appears in the next shot, the clipboard is missing.
Born Again Krabs (aka A Penny Saved) / Safety Freak (aka I Had An Accident) - S3-E17
Continuity mistake: In "Born Again Krabs", Mr. Krabs drops the coins that the Flying Dutchman gave to him on the floor. In a few shots, when the Flying Dutchman comes back, the coins have vanished.
Chosen answer: You need to provide a little bit more information to be able to answer a question like this. In what region is it not being shown? I see it being replayed here in Australia fairly frequently. As for a general reason, there does not appear to be any for why it specifically might have been taken off the air in any country or region. Like any show certain episodes can sometimes not be replayed for long periods for unknown reasons.
Lummie ★