Learn Dutch: Hierdoor ontstaat de kortsluiting. - Because of this, the short circuit occurs.

Because the sentence starts with the causal adverb hierdoor. In a standard Dutch main clause, the conjugated verb must be in the second position (the V2 rule). When you put hierdoor in the first position to emphasize the cause, the subject (de kortsluiting) is forced to move after the verb.

Could I use daardoor instead of hierdoor in this sentence?

Yes, but it slightly changes the nuance. Hierdoor means "because of this" (referring to something very immediate or just stated), while daardoor means "because of that". The distinction is exactly the same as choosing between "this" and "that" in English.

Why use hierdoor instead of door dit to say "because of this"?

In Dutch, when a preposition like door (through/by) is combined with a pronoun like dit (this) or dat (that), they merge into a pronominal adverb. Dit becomes hier- and attaches to the preposition. Saying door dit sounds unnatural; hierdoor is the standard way to express "because of this" or "due to this".

The English translation uses "occurs", but doesn't ontstaan mean "to originate"?