Audio problem: After The Mask gives his "Oscar winning speech" and Dorian sticks a gun in his face, "You're not going anywhere" can be heard. No one says this and was poorly recorded.
Visible crew/equipment: After a masked Carrey leaves Landfill Park, an aerial camera and person swings back and forth near the top of the screen in the background during the conga line dance.
Suggested correction: Those aren't camera people, they are supposed to be tactical police officers on a rope line who get involved with the singing/dancing by swinging and doing some aerial flips. We'll ignore that the ropes just go up into the sky, but that is the kind of comedic movie this is.
Audio problem: In the scene where Milo jumps at the cell window to save Ipkiss, Stanley says "good boy," but his mouth doesn't move. (01:13:00)
Revealing mistake: Dorian and his men are watching what we're assuming is a live feed from Tina at the bank. At one point the "video" stops as you can see a guard freeze. From that point on the video is a still picture.
Suggested correction: If you look at the top of the screen showing the bank video, you can see a multicolored distortion. This shows that they paused the video feed.
We don't see them pause the video.
We also don't see their hands, so one of them easily could have paused it.