A Frame Challenge is often related to an XY problem
And those are a problem throughout SE.
Quite often it is simply a matter of reading just a little between the lines. I just saw a question of "how do I get her phone number?" (Y) And I innately read that as "How do I court her?" (X). But would answering X answer the question?
Frame challenges should be necessary
The faceplanting fail of a frame challenge is when everyone else can answer it without reframing.
First, let's set aside an exception. "I want to run power to my shed. I bought and buried 300' of 2-wire cable. How do I do that?" -> You can't / You can't / You can't / You can't / Transformer. You can't fault the vast majority for not anticipating the work of a "steely-eyed missle myn". Nor should you be punishing the odd one, FYI. When this happens it's a no-fault situation.
But when you insist on a frame challenge, and others don't need it, that means you are the one swerving out of the way. And we have a right to ask/examine why you are swerving. Often it's to grind an agenda of your own tangential to the question. A person who wants to grind that agenda should ask their own question to create a proper place for the discussion... preferably on /pol/ :)
In that case, you should not be answering that question. For some people, that can be simplified down to "you shouldn't do frame challenges".
Honestly, I recommend that someone who does a frame challenge, and watches as others plural reasonably answer the question straight, just go ahead and delete their answer, and consider it a learning experience.
"You can't" is a particularly noxious frame challenge
Everything I said above applies -- squared -- when the frame challenge is "you can't do that".
It's a very bold statement and needs very bold proofs.
It better be answering a question like "I'm drunk, how do I drive home safely?"
It's so much fun to slam down "You can't". But that is really where you need to pause and think it through. It is unduly discouraging to the asker, and creates drama where it need not be. It's almost like picking a fight (again see "agenda"). That fun happens at the expense of the community, and that's not cool.
It also tends to resemble superior schoolmarm lecturing, which violates rules like "be nice" and "assume good faith/intent" but again is oh, so fun. Also the fact you are assuming the person is super dumb, making a cartoon caricature of them (a strawman) so you can kick them - Very un-SE.
Find a way. That's what answering is.
I will grant an exception for literary tricks, where you use it as a lead-in to a straight or reasonable answer, i.e. just using it as a bit of clickbait. Wait. Why am I giving that exception?
don't do it, does that make it off-topic immediately?