Continuity mistake: Zordon disappears for two shots (wide shots) when Ivan Ooze is destroying the Command Center. (00:20:50)
Continuity mistake: At the end of the first scene (skydiving) Bulk and Skull land in a construction site. A worker goes over to them and starts talking. At this time the guys still have their parachutes on. It then cuts to the worker and back to them and not only are the parachutes off, they are nowhere to be seen. (00:07:10)
Continuity mistake: When Ivan tells the parents to leap to their death, they all drop their boxes on the floor, but when it shows Fred's father, they are holding the boxes, then when it shows them walking out there are not any boxes on the floor.
Continuity mistake: When the Rangers are rollerblading, it shows Billy, Tommy, and Kimberly jumping. When it shows them landing, they land Tommy, Kimberly, then Billy. (00:06:30)
Continuity mistake: When the Rangers are first talking to Dulcea, the front view shows her standing up straight, but the back view shows her knees bent. (00:39:20)
Continuity mistake: During the fight scene with the Ooze men, Rocky (Red Ranger) and Adam (Black Ranger) jump down to a lower level of the parking structure landing with Rocky at the left of the screen and Adam on the right. Soon after, several Oozemen jump after them, but when they land Rocky and Adam have switched sides. (00:23:50)
Continuity mistake: Dulcea starts spinning the sticks to drive away the Tangu warriors. First off she is spinning the sticks in her hands. Camera changes and now she is holding a handle to spin them. (00:38:00)
Continuity mistake: When the Rangers are receiving the "Great Power" from the temple, Adam's ninja zord (Frog) is flying around Billy, and Billy's ninja zord (Wolf) is flying around Adam. (01:04:00)
Continuity mistake: When Ivan starts the ooze pumping at the toxic chemicals plant, when the shot changes, the ooze is clearly water. (00:36:20)
Continuity mistake: Near the end, when the Ninjazords begin to combine, you can see the Wolfzord (right arm) and Apezord (left arm) attach to the Bearzord (chest section), in this process you can see that the Cranezord (head section) is already attached but in the next shot it comes in for attachment.
Continuity mistake: When the Rangers are reviving Zordon, they set their helmets directly in front of them, but when they move around Zordon's platform, the helmets seem to have followed them. Then when the emblems are coming out, the helmets have disappeared. After they move back together, the helmets have moved back. (01:24:55 - 01:26:20)
Continuity mistake: When the Rangers return to Earth, there is the giant scorpion in front of them and the standing bug behind them, but when they call on their Zords, the standing bug behind them has disappeared.
Continuity mistake: During the ninja battle against the rock monsters, Tommy swings on a vine over to Kimberly and kicks the beast away from her. If you watch closely Tommy kicks the monster with his back to the screen but in the close up shot of him kicking the monster, his foot is facing towards the screen meaning his body switched sides. (01:01:05)
Continuity mistake: We see Ivan form from all the goop in the egg. When the Rangers arrive, after Ivan is out, the egg is still very full.
Continuity mistake: When Fred's father arrives home, the street is empty. But after he is zombified not even one minute later, the street is filled with people. (00:43:45)
Continuity mistake: After the Black and Red Ranger jump down off the platform during their fight with the ooze men, it shows two ooze men jumping after them, but when they land, there are three ooze men. (00:23:55)
Continuity mistake: When Fred's father pulls into his driveway, you can see the raised part of the dashboard where the steering wheel, odometers and such sit, on the lower right side of the windshield. Then when he gets out of the car, he climbs out of the left side and you can see there's no steering wheel there. (00:43:00)
Continuity mistake: When the Rangers teleport to the command centre for the first time all their roller blade gear has vanished. (00:09:13)
Continuity mistake: When the Tengu Warriors are first forming, you can see there are 9 distinct piles, but when fully formed there are 10 unique warriors.
Continuity mistake: When the rangers find the temple, we see Kimberly jump up the few step in an overhead shot. Camera changes to Tommy and she climbs the steps again in the background. (00:57:40)
Answer: They weren't even considered to appear in the movie considering there were so many other changes (different suits, new Command Centre etc). Also the movie has been widely accepted as out of continuity with the TV show, so their disappearance doesn't really mean much.