I can imagine Genitive "присваивания" ("of an assignment") in a sentence like "This issue arised as a result of an assignment a particular value to a dynamic float16 variable when all temp registers were full."
(and something similar if the word is used as "taking over ownership", like "The person mentioned was involved in a case of misappropriation in 2006, case subject to appeal later in.....")
Just like in English, in Russian it would be more "natural" and less bookish to use a verb ("there was a problem when we assigned...", "when a value was assigned") rather than a deverbal noun. In this particular case, of course. The sole use of this word already marks the supposed style of a passage as stilted and formal; it is certainly formal writing, not everyday speech.