The Class Runs Into A Convenience Store - S1-E10
Continuity mistake: At the very end of the episode, Kyle, Ethan and Kat are standing in a line looking at Lina and Richie. On the close up shot of the three of them, Ethan is standing next to Kyle, but when the shot is from above, Kat is now in between them, with no time to have moved.
Chosen answer: Due to creative differences she has left The Class, with her last episode being that of Jan 8.
Boobra