If the parent universe is running an exploration of possible universes according to consistent laws of physics, upon crash it will probably backtrack the simulation to a previous timestamp, fiddle a little in the phase space, then continue forward.
One way to make it crash is making the simulation crawling to a stop by requiring always more computation to be done by preventing the simulator to take shortcuts in the computing process.
A backtracking mechanism to preemptively avoid crashes is probably deeply rooted in the form of an implicit solver in the time-stepping mechanism to guarantee the consistency of the tangled causal chains.
Which mean it is probably possible to exploit it from within the simulation. By deciding to do heavy computations in the future, depending on what you observe of the past and its implied future according to your previsions, you can pick your past among the physically possible universes. To guide the simulator to the future you desire, you have to create a consistent alternative past toward your possible future.
To not violate the second-law of thermodynamics which has to always increase (monotically) in your universe, you therefore have to reduce the entropy of the past by minimizing it (down to the origin of time, up to your current view point from inside the simulation), aka simplifying history, to give your physical self some room to shape the path from past to future the way you want.
But by the time, you are able to get your time-machine to work, you'll have realized the futility of it and went to the upper plane of existence.