I saw this in a brochure for a professional course and book.

Problem:
The hyphen is misplaced.

Explanation:
Wow. Talk about nonsense.

The publisher of the brochure ought to be ashamed, especially given the brochure’s target audience (professionals in a field that shall remain nameless).

First, the word “nonsense” does not have a hyphen between its two syllables.

Second, given that “no” plus a noun (“nonsense”) are modifying another noun (“approach”), a hyphen is required between “no” and “nonsense”.

It boggles my mind to imagine how the author of the brochure decided to write this headline in this way. Perhaps the decision was driven by fear of hyphenating incorrectly.

Solution:
“A no-nonsense approach”