Situation is this: i have a main .mxml file from which i imported custom component which is basically Accordion with two elements and inside them is TextArea control for each one. I have a function in main .mxml which displays that component as a popUp (using popUp manager class) and populates those two TextArea controls with some text. I can populate first one TextArea just fine but when i try to populate second one the same way i did the first one i get this error:

Code:
TypeError: Error #1009: Cannot access a property or method of a null object reference.
    at SMC/popUp2()
    at SMC/writeToOutput()
    at SMC/___SMC_Button1_click()
I don't really understand this error and i am not sure what i've done wrong, can someone please help me?

thank you