In the flashback of Rita being sealed away at the end of the battle between her and Zordon, the container she is trapped at is obviously NOT the dumpster she is freed from at the beginning of the Mighty Morphin Power Rangers series. This is because the filmmakers used footage from Zyuranger's finale, in which Bandora (their equivalent of Rita) is resealed away at the end of the series, and by this point the original dumpster had been destroyed in that series. This, it becomes a continuity error in MMPR, if said footage is considered canon.