Powerful Meditation explicitly states that it can be used on a spell or skill which was "negated by a defense.". Under the Defenses section, No Effect is specifically listed as a defense. Not sure of the confusion here, but Powerful Meditation definitely allows meditation when something you use is stopped by a "No Effect" call.
An ability which hits a target and is stopped by a defense (including "No Effect") cannot otherwise be Meditated. It is materially different from a miss.
Note that things which hit an in-game barrier (like a Ward, Wizard Lock, Circle of Power or Wall of Force) which cannot be physrepped to stop an attack count as a miss. If you throw a spell at someone and it passes through an active CoP, they are certainly not affected, but it's as though you threw and hit the wall of a building. They might call "No Effect" to inform you that they aren't taking it, although it might be more proper for them to point at the Circle and note "Active Circle, I'm not taking that".
-Bryan Gregory
ARC
An ability which hits a target and is stopped by a defense (including "No Effect") cannot otherwise be Meditated. It is materially different from a miss.
Note that things which hit an in-game barrier (like a Ward, Wizard Lock, Circle of Power or Wall of Force) which cannot be physrepped to stop an attack count as a miss. If you throw a spell at someone and it passes through an active CoP, they are certainly not affected, but it's as though you threw and hit the wall of a building. They might call "No Effect" to inform you that they aren't taking it, although it might be more proper for them to point at the Circle and note "Active Circle, I'm not taking that".
-Bryan Gregory
ARC