Error #1009 , Help me please, it's very important );

[RodrigoCC]

Hello everyone, this time I have a problem with error 1009, what happens is that when I click a button to go to another frame I get the following
TypeError: Error # 1009: Unable to access a property or method of a reference to a null object.
at PINTARFINAL_fla :: MainTimeline / frame208 ()
at flash.display :: MovieClip / gotoAndStop ()
at PINTARFINAL_fla :: MainTimeline / backwardLevel5 ()

It happens in frame 208 and I do not know why,I can't send the fla file here, I don't know why, you can write me by private message if you have the answer it, it only happens when I click the back button in frame 210.

[kglad]

tick file>publish settings>tick "permit debugging".  retest.

the line number (as well as the frame) with the reference to a non-existant object will be in the error message.  if that doesn't make the solution obvious to you, copy and paste that line of code here.