Other mistake: Beast Boy and Wildebeest fight in a cage suspended in an endless room, with no solid ground underneath. But during the fight both combatants keep stepping onto the gaps formed by the cage bars without their feet falling through, as if the cage bars on the bottom side are merely painted onto a solid surface. For instance, watch Beast Boy's feet when he turns into a skunk.
Other mistake: Among the Titans groaning over Beast Boy's "brainfreeze" joke, we see XL Terrestrial, the pale-turquoise alien-looking guy with two antennae who can grow to large size. Again a mix-up of hero and villain identities, since XL was in the H.I.V.E. and the Brotherhood of Evil and should therefore not be among the young heroes. You will also see the Puppet King by Jericho.
Other mistake: When Red Star introduces himself, he takes off his parka with both hands. But as it drops to the ground, you can see the fingertips of his hands on top of the screen, standing completely still. This setup looks unnatural, as if he had suddenly taken off the parka with some telekinetic power.
Other mistake: When the probes are going off in the Titans, including Robin, Slade rips off his arm piece that houses the red button. When he does this, the probes stop. However, it would have required clicking the button again rather than just breaking it off the rest of his suit. (00:19:45)
Other mistake: Cyborg/Stone attacks his own robot duplicate starting from near his fellow Titans, with his back turned to them. But after he has finished smashing it to pieces (thereby ruining his disguise), he suddenly is positioned so that he actually faces them, without having made any turn-arounds, since he charged his duplicate head-on.
Chosen answer: It is located in California, as shown in "Teen Titans: Trouble in Tokyo". Possibly San Francisco as seen in the comics.
MasterOfAll