Aklıma 2 sebep geliyor:

1. script timeout kısa

2. error 1502'yi almadan önce aşağıdakini almışsınız:

Error #1503: .... at fl.managers::FocusManager/removedHandler()

removedHandler hata vermiş gibi...

1502 - A script has executed for longer than the default timeout period of 15 seconds.

A script executed after the timeout period. (The default timeout period is 15 seconds.) After this error occurs, the script can continue to execute for 15 seconds more, after which the script terminates and throws run-time error number 1503 (A script failed to exit after 30 seconds and was terminated.)

1503 - A script failed to exit after 30 seconds and was terminated.

The script was still executing after 30 seconds. Flash Player first throws run-time error number 1502 (A script has executed for longer than the default timeout period of 15 seconds.) if the script executed more than 15 seconds, which is the default timeout period. This error occurs 15 seconds after Error 1502 occurs.

Bir de eğer sürekli değişen bir veriyi okuyup kullanıyorsanız, bi yerlerden null veri girişi olduğunda anlamsız patlamalar olabilir bu tarz projelerde.