The Chrono Ramdomization Barrier protects the Forge of Creation from intruders and makes it out of sync with time.
Ben and his team ran into the Chrono Randomization Barrier when they were heading for the Forge of Creation. It appears to be a barrier that if touched by any individual, it will bring their past self into the present.
This apparently only works for living beings however, as it did not bring an earlier version of the Rustbucket 3 when its wing got stuck inside the barrier. When Ben fell into the barrier, he was saved by Gwen and to their shock, Ben's 10 year old self soon stepped out of the field, joining them in their fight against Aggregor.