The correct answer to this open question is the following.
You did not include any reference, text, or further context. We do not know what is the topic of controversy.
However, by doing some research we can help you with the following.
If you are referring to the controversy between formal science vs. pseudoscience, then the issues or problems that tend to lead to such controversies are the lack of evidence used by pseudoscientists when trying to prove something.
True scholars and scientists know that the scientific method is the only way to validate a phenomenon. The results can be repeated one, two, and three times, and scientists had to validate the results every single time. Then, we can say that something has scientific support and validation.
On the contrary, pseudoscientists often times do not include validation, just opinions, and general comments based on their own perspectives.
