TypeError 1009, began appearing randomly after adding new button code - actionscript-3

Question

SOLVED: It was a two stop functions. Two. Stop. Functions. AS3 can be so annoying sometimes.
I am making a space invaders style game for a school assignment. I was adding in a button to go between frames and I deleted an unnecessary layer that contained a single sprite in my game, which I added back onto the main code layer. Then after attempting to restart my game to check the button, I began receiving a TypeError Code 1009. It is stating that there is an error with MainTimeline/moveBullet() and, MainTimeline/eFrame(). These sections of the code were not altered whatsoever during the creation of the button or movement of the sprite, however, as the bullet is linked to the moving sprite I think the error may be there. I'll put the code below, if anyone knows how to fix this specifically or has a general idea of how to do so please let me know. This is due in a few hours and would greatly appreciate a quick fix. Thanks.
Re-named sprites, re-typed code sections returning errors again. Most fixes appear to be in instance names, corrected them and no fix.
this.addEventListener(Event.ENTER_FRAME, eFrame)
function eFrame(e: Event) {
controls();
restrain();
moveBullet();
enemyHit();
barrierHit();
function moveBullet() {
if (bull.visible == true) {
bull.y -= bulletspeed;
if (bull.y < 0) {
bull.visible = false;
}
}
}
The game had been running fine until this point. The character would move along bottom and shoot up at "bad guys". Bullets were removing bad guys. Now I get the usual super fast run through frames repeatedly. NO Compiler Errors, just output, being
TypeError: Error #1009

Answer 1

"I deleted an unnecessary layer that contained a single sprite in my game, which I added back onto the main code layer. Then after attempting to restart my game to check the button, I began receiving a TypeError Code 1009."
Possible solutions:
(1)
Did you also give the Sprite an instance name? I suspect the name bull is what's expected.
(2)
Eliminate that the problem is in moveBullet(). Disable the call and if the error still exists, then the problem must be between variables bull and bulletspeed.
Comment the call movebullet() in function eFrame:
function eFrame(e: Event)
{
//moveBullet();
....