Double preposition?

I am reading a journal and found a sentence which seems wrong. The sentence is,

It is apparent that the errors originate from outside the model.

This sentence used from and outside together which are supposed to be preposition here. I guess double preposition is not allowed in the English Grammar. May someone clarify this point for me? Moreover, I rewrote the sentence. May anyone check whether my modification makes the sentence correct?

The modified sentence:

1.) It is apparent that the errors originate outside the model.
2.) It is apparent that the errors originate from the outside of the model.

Any help are appreciated!

UTC +8:00 12/13/2013 4:05 PM

Follow-up question:

So double preposition is not incorrect. But in this example, it seems redundant to use "from outside". Like my 1st alternative, just "outside" is enough to express all the meaning. Should we avoid double preposition in this case? Or does it express some specific meaning that I have not understood yet?

Answer

I don't recognise the idea that there might be something wrong with "double prepositions" in English. Obviously it's not true in general, but I can't even guess why anyone would think it true in any context.

For the specific usage OP asks about, it's just a matter of whether we normally speak of things originating somewhere, or originating from somewhere. As this NGram shows, we actually use the first form 2-3 times more often, but there's nothing wrong with the second in originate from outside.

That NGram also shows how rarely we use OP's suggested originate from the outside. What this doesn't tell you is that the outside would be extremely unlikely in OP's exact context, because when we include the article before outside, we're normally referring to the outer surface (of a container, for example).