Literal and semantic translations are worlds apart in terms of both philosophy and execution.
The easiest way to take your document translation down the wrong road, of course, is by getting lost in the weeds of literal translation and thus losing sight of the meaning of it all. The wrong word choice in the target language can change the meaning of the sentence entirely, with the end result that a perfectly accurate translation can in fact be perfectly useless – or, worse, harmful – because the meaning has been lost to some poor vocabulary decisions. Semantic errors in translation come in many varieties, but the most common I’ve seen are Cross-Association errors and Language Switching errors.
In a cross-association error, there are several words in the target language but only one in the source language – or, possibly (and perhaps most commonly), the translator is only aware of one word in the source language. This is one reason why most translations are performed by the native speakers of the source language. The possibility of selecting the wrong word to translate with is high, unless you are very familiar with the target language and know the subtle shadings of meaning that can exist between two different words that on the surface mean more or less the same thing.
In a language switch error, the translator simply does not know how to translate the word, or for some reason decides that the original language itself is most suitable and leaves it untranslated. This is never acceptable, as it abandons the entire purpose of translation in the first place, and leaves the reader of the translation struggling to glean the meaning of the word from context. If readers are struggling for context, you have automatically failed in your attempts to translate a work.
Semantic mistakes are challenging to translators for the simple reason that they are mistakes of comprehension and understanding, and as a result your lack of comprehension often hides your mistake. In other words, you can’t know you’ve made a mistake if you don’t understand what the problem is in the first place!