It depends on the context, and you've provided too little of it for a definitive answer.
Grammatically, there's no reason an article must be included after the phrase due to. For example:
We can't say for sure if this week's heat wave is due to global warming.
There is no need for an article before the phrase "global warming" in that sentence, so there's no need to put one there.
However, if I said:
There has been a scorching heat wave in Texas this week. There has also been an unusually high number of road rage incidents, but we can only speculate if this was due to the higher temperatures.
Here, the article works, because the noun higher temperatures was previously mentioned (not by name, but by implication, when the heat wave was mentioned).
In short, in a phrase like the one in your question, the use (or non-use) of an article depends on the words after the article, not before. For example, we could say:
The project was late due to the complex hardware and software designs inside the control unit.
More and more projects are experiencing cost overruns due to complex hardware and software designs.