Let's assume the universe is fundamentally a system of computations, in which the sum of past calculations leads to a certain state at any given point in time. Let's also assume that all the calculations happening at a certain time consume too much processing power for the host to calculate, which would mean there have to be optimizations, similar to only calculating the field of view of the player in a video game. The latter would result in a state which is only partially calculated. Can both assumptions be true at the same time so that, at least in theory, each state can be calculated, even if past states are incomplete?
It would depend on the other rules of the universe, and the interdependence of the parts that are calculated in full fidelity with the parts that are lossily optimized. It is widely believed that events in our universe are affected only by events in their past light cones. If this is true, the computer or mind simulating our universe could postpone calculating a region of the time-space continuum, as long as that region is expanding at the speed of light. Once more processing power is acquired, or the demand for processing power is lowered, the computer or mind could fill in the empty region from the past to the future, until it catches up with the rest of the universe. Keep in mind, that if the universe is a simulation, it could be paused or slowed without affecting the laws of physics.

So to answer your question, you can calculate an incomplete but regionally lossless present state from an incomplete but regionally lossless past state, but you can't calculate a complete present state from an incomplete past state, if the present is truly dependent on past states.