Your Shoe's Untied / Squid's Day Off - S2-E2
Continuity mistake: Near the start, at first you can see words on the menu board, then you can't. (00:05:50)
Your Shoe's Untied / Squid's Day Off - S2-E2
Continuity mistake: In "Squid's Day Off" when Mr. Krabs is washing the money that came out of the register, Spongebob taps him on the shoulder while the faucet is still on. When Mr. Krabs drops the dime into the sink, the water turns off without anyone touching the handles.
Your Shoe's Untied / Squid's Day Off - S2-E2
Continuity mistake: Spongebob says, "We forgot to change the close sign to open," yet when Squidward walks out throughout the episode there is no sign at all.
Your Shoe's Untied / Squid's Day Off - S2-E2
Continuity mistake: When SpongeBob is sad because he can't tie his shoes, you see is night. When Gary ties his shoes, suddenly it becomes day.
Your Shoe's Untied / Squid's Day Off - S2-E2
Continuity mistake: In "Squid's Day Off", sometimes Squidward's house door opens to the left, and sometimes opens to the right.
Your Shoe's Untied / Squid's Day Off - S2-E2
Continuity mistake: In Your Shoe's Untied, when Spongebob takes the patty to Squidward, it's just a patty with lettuce, but in one shot, you can see cheese and pickles on it.
Your Shoe's Untied / Squid's Day Off - S2-E2
Continuity mistake: In Squid's Day Off, when all of the coins go out of the cash register, you see 14 coins drop. When Squidward picks up the coins, there are only 12.
Your Shoe's Untied / Squid's Day Off - S2-E2
Continuity mistake: In "Squid's Day Off" Squidward gets mad at Spongebob for ringing a bell over and over again. It shows the bell in the window to the left. Later, when it shows Squidward throwing the cash register onto the ordering desk, the bell is gone from the window. In the next shot of Spongebob, the bell is back in the window. Then, when Squidward shouts "No." the bell is gone again.
Your Shoe's Untied / Squid's Day Off - S2-E2
Continuity mistake: In "Your Shoes Untied", when he is in the Krusty Krab kitchen. In between shots when Squidward keeps asking Spongebob to give him the Krabby Patty, the patties on the grill disappear and reappear between shots.
Your Shoe's Untied / Squid's Day Off - S2-E2
Continuity mistake: At the beginning of "Squid's Day Off", There is a tiny bell painted gold sitting on the opening between the kitchen and restaurant. When the shot changes, the bell disappears, then reappears when the shot changes again.
Answer: I believe this is the Season 6 episode "Spongicus".