I've made posts about this on some of the other threads but i'll sum up my main point here.
Having both play tested the game and seeing various posts on the subject, it is pretty clear that there is an issue regarding Npc's (both humanoid and animal) and monsters (both of which i'll now collectively refer to as characters) when the game requires them too roll a skill check or attribute which they don't have listed on their character sheet (be it opposed rolls, awareness checks, resistance rolls against magic etc).
Now i really like the overall streamlined approach Free League has taken for the game (its one of the main reasons i am interested in it). And i understand the intention is that characters are meant to have minimalist character sheets so it is quick and easy to get a game going.
But i think they may have cut a bit too much, as currently as a GM i can find myself in these weird positions of being asked to roll something that i don't have any material to use, and i think it is a big problem.
Now some things i think can be solved by letting the players do a roll instead (such as rolling bluff rather than the npc making an awareness roll when using the Disguise heroic ability), but for the bigger issues such as opposed rolls i think there are three solutions.
1: the GM only rolls attack, evade, parry and healing checks in combat, any other roll are done by the players with some rule to modify the difficulty (such as a skill penalty, reducing the odds of success).
This removes the need for most character stats sense the important stuff is done by the players.
2: the characters use 1-2 substitute stat, which they roll if they do not have the skill in there sheet. This gives you something quick and simple to use.
3 (which i think is what most are leaning for): the character has there attributes listed, along with the skill base value for that attribute ,so for example if they have Str of 18 it is written as STR 18 (7), and the character lists ONLY the skills they are trained in(so in the above example, if a character is trained in SWORDS but not HAMMERS, you only list SWORDS as SWORDS 14, HAMMER is covered by the Skill Base Value.)
This means there is more work to create a character, but you have everything covered.
In the grand scheme of things,i am not picky with how this is addressed, aside from keeping things streamlined, but as it stands i think this is a big issue with the game as it currently is.
(Edit: Made some spelling corrections, writing a lot on a phone is hard)