Anomaly

The Anomaly was a rift in the space-time continuum created by Bender, when he invited his time paradox duplicates to "Stick around instead of coming up when they were logically supposed to" when he went back in time with the machine language time code. Each other Bender was thus a time paradox duplicate, and was doomed. The hundreds of doomed Benders began spontaneously exploding, setting off a chain reaction which apparently tore the universe a new one.

Beyond the Anomaly was another universe, which is where the sole inhabitant Yivo dwelt. The Anomaly is surrounded by an electromagnetic field that expels all electrical beings and devices (such as robots and spaceships) upon contact, while living things and non-electrical materials (such as wood) can pass through without difficulty, though larger objects appear to need extra force when doing so. After a few months of existence, the Anomaly suddenly was sealed (suggestively by the timing, Yivo did this), cutting off all those on that side of the universe from this one forever.

Trivia

 * The Anomaly resembles the Cracks in Time, prominently seen in Doctor Who Series 5.