Why i can't change the CFrame of the player's character?

Try using set primary part cframe instead.

Here is a very useful link: SetPrimaryPartCFrame

Here, if you want to set the character's CFrame, it should look something like this:

--after you have defined the character and everything, done all the if statements, once you want to move the character:

character:SetPrimaryPartCFrame(CFrame.new(85.5613, 15, -496.286)

If that doesn't work try adding a vector3.new infront of the new script above, like you did in your original script. You shouldn't need to though, i just haven't checked.

If this has helped you, please accept this answer :) thanks