# Possible bug in Flash Player - null object reference error **URL:** \ **Category:** flash\ **Created:** [February 17, 2009, 6:52am UTC](https://forum.kirupa.com/t/possible-bug-in-flash-player-null-object-reference-error/282057 "2009-02-17T06:52:22Z")\ **Posts on this page:** 1\ **Page:** 1
**Author:** ![missileh](https://avatars.discourse-cdn.com/v4/letter/m/898d66/32.png) [@missileh](https://forum.kirupa.com/u/missileh)\ **Post date:** [February 17, 2009, 6:52am UTC](https://forum.kirupa.com/t/possible-bug-in-flash-player-null-object-reference-error/282057/1 "2009-02-17T06:52:22Z")
I am currently working in an AS3 project and experiencing a problem due to a bug (well, perhaps…) in Flash player… What i am doing is: On frame 2: I set the visibilities of about 8 to 9 buttons that are placed at design time. Then I add event listeners to them. On frame 4: There is a ‘Back’ link that takes me on to frame 2 again. Now, when the play head goes back to frame 2, I get a runtime error showing: “Cannot access a property or method of a null object reference.” When I inspect the variables, I find that all the buttons have been instantiated apart from one button (error occurs when visibility of that button is being set)… Checking the index value of that button, i get 10. Now if I change the indexes at design time and place some other button at that index, error occurs for that button (ie. the button that i just placed at index 10). I came across this error last week as well and assuming this as a flash bug, I arranged a hack. Last time the problem took place at index 3. So i just put a temporary movie clip outside the stage at index 3. (And if i debug it, i find that this temporary movie clip does get null when i move back to frame 2 from frame 4)… In case of flash bug, i can use this workaround, but is it possible that on different machines, this problem will occur for different indexes… (ie. sometimes on index 4, sometimes index 8 etc…)? There is a bug described on the adobe site… I dont know if that is related with the issue I am experiencing because the workarounds mentioned dont work for me… [SIZE=1] Official bug description: [http://bugs.adobe.com/jira/browse/FP-43[/SIZE]](http://bugs.adobe.com/jira/browse/FP-43%5B/SIZE%5D)