It is "the" problem, as it makes it impossible to tell what is natural and what is intentionally created by advanced civilizations, making it impossible to know

It is "the" problem, as it makes it impossible to tell what is natural and what is intentionally created by advanced civilizations, making it impossible to know if the paradox even exists at all, since we may be looking at "obvious" signs of alien activity, yet be completely incapable of recognizing them as such.