In its broader sense, problematic means anything that "in some way—through its meaning, or the unstated assumptions behind it—reinforces unjust beliefs or an unfair system". It is largely tied to the Social Justice movement online. In its fannish context, this could be characters, creators, actors, casting decisions, storylines, quotes, costumes, or even fanart of racist, misogynistic, sexist, homophobic, or appropriative natures.
A problematic fave is a person or thing that has exhibited problematic behavior but for whom the speaker's affection has not diminished. A number of blogs titled "Your Fave Is Problematic" have been active over the years, and are dedicated to compiling evidence of celebrities' problematic behaviors. There have also been discussions of whether or not YFIP is in itself problematic.
To be an unproblematic fave is a high praise in fandom. This is a person or thing that has not exhibited any problematic behaviors and has probably, in fact, acted or spoken in an educated and self-aware manner. They are also often a Cinnamon Roll.
Fannish Usage and Discussion
problematic. it's just so vague. like, if something is racist and sexist, say "this is racist and sexist," not "this is problematic." it's too....cutesy, i guess. by not saying exactly what the problem is, it's like you're ignoring it. i can get using it certain ways, when talking about a group of things that have issues, but they don't all have the same issues, but it shouldn't be used as a replacement for actually saying that something is racist/sexist/homophobic/etc.
- The rise of the anti-fandom fandom, Archived version at The Daily Dot (May 2013)
- Femslash Revolution's 2017 statement