Plot hole: When the flying saucer first appears, it is supposed to be 4 AM. But the grave diggers are still there from the burial of Bela Lugosi's wife.
Visible crew/equipment: When Colonel Edwards enters the General's office, the moving boom mic is visible at the top of the screen.
Plot hole: Eros makes it very clear that his race does not 'cling to life.' If this is the case, then why is he so determined to save everybody?
Suggested correction: What he's saying is that they don't cling to their individual lives, placing them second to the fate of their planet. Note that from Eros' point of view, the survival of the whole universe is at stake.
Continuity mistake: In the scene on the back yard portico where the cop is backed up to the other cast members, the male vampire knocks him down to the ground. It then shows the green 'rays' shooting off the landed saucer and the vampire crumples to the ground. A cast member throws off the vampire's cape revealing a skeleton. At this point the cop is missing from where he fell in front of the vampire. Next shot someone helps the cop up from the ground where he is lying almost touching the revealed skeleton. Also, the skeleton used for the skinny male vampire is the same one used for the grossly overweight Tor Johnson.
Factual error: The gunpowder made in the 1950's didn't produce the clouds of smoke we see whenever the police fire their weapons, but those of the 1870's did. Ed must have nicked some ammo from the Lone Ranger's property master, eh?
Revealing mistake: Why are all of the space ships the same exact size as the planet?
Plot hole: The aliens' plan ("plan 9") is deeply flawed. The aliens resurrect the dead to make earth people accept the aliens' existence. However when Eros reports to his leader, he says that "none of the risen have been seen." What's the point of raising the dead if they aren't seen anyway? And while later, yes, the old man enters a dwelling and is by everybody, anything before that was just a huge waste of time on the aliens' part, making the first phase of the plan completely senseless.
Revealing mistake: The inside of the spacecraft is populated with electronic equipment sitting on tables. You can easily identify a Hallicrafters short-wave receiver which the alien tries to smash on Jeff Trent's head. In the B&W version, you can even see manufacturer labels on the front of the units. They are missing in the colorized version.
Factual error: The cemetery is full of bare branches of medium to small 'plants'. Since this is southern California, they should have leaves.
Revealing mistake: In the cemetery, you can see the actors' shadows on the fake sky.
