PRECISION STRIKE
When this character makes an attack, it can’t be evaded, and the damage dealt can’t be reduced below 1 or transferred.

INVINCIBLE
Half of damage dealt to this character is ignored.

IGNORES:
Is not affected by or treats the stated property or effect as if it didn’t exist or happen.

Question:
A character that has invincible, is attacked by a character that has does 1 click of damage with PRECISION STRIKE. Would the character with invincible still receive 1 damage ?

They would not take any damage from a 1 damage attack with precision strike.

Ignoring half of 1 damage rounded up is 1, so you ignore 1 point of damage.

Yes, a character with invincible would take a minimum of 1 damage when hit by a character with precision strike

As rules now stand, invincible ignores the damage. Ignore is different than reduce. Penetrating is can't be reduced; still can be ignored. You need unavoidable tonotbeignored

This is incorrect. Invincible ignores damage, Precision Strike does nothing to prevent that from happening.

This is incorrecr. PS cannot be reduced to less than 1 but it can be ignored

IMPERVIOUS
When this character is dealt damage, roll a d6. On a result of 5
or 6, the damage dealt is reduced to 0. On a result of 1–4 , the damage dealt is reduced by 2.

jltw061 Mazahs! has Invincible on his first click and he has a Trait:

YOUR DEATH BRINGS ME POWER:
When Mazahs! KO's an opposing character, choose a standard power that character possessed on any click. Mazahs! can use that power for the rest of the game.

I have read that jltw061 Mazahs! could not use Impervious and Invincible, because Powers that reduce or ignore damage do not stack, and a character can only choose to use one and not both. Is that still correct ? Or has it changed ?

Yes it's still correct that they do not stack. Though he gets to choose which one to use each time he is dealt damage.