I would alter this to be "MC's unique personal problem".
Using the word "internal" is trick here, because almost all problems can be seen as internal and external. Missing a leg? What's the problem: your lack of a leg, or your attitude about missing a leg? This is why Dramatica focuses on Approach.
This is a good way to think about it, but there is a better way.
There are potentially a lot of third party solutions in the movie. The IC is the solution that is most different from the MC, and the most interfering. It is best interpreted from the MC's perspective, because it does not only exist inside the IC.
Can you say this in Mandarin, and I'll see if I can get someone to translate it for me?