Flash Builder – “Content Assist” did not complete normally.
Since FlashBuilder beta there was an annoying bug with content assist: java.lang.NullPointerException in both the eclipse plugin and the standalone version, while trying to use autocomplete on variable names or properties or any other place.
The solution for fixing this problem is simple, but unfortunately not final. (Meaning you will have to repeat this procedure each time the FlashBuilder is failing on us)
Steps to fix:
1. Close FlashBuilder (or Eclipse if using the plugin)
2. Navigate to [Current_User_Documets_path\Adobe Flash Builder 4\.metadata\.plugins\] and delete the folder [com.adobe.flexbuilder.codemodel]
(for ex on Vista: c:\Users\myuser\Adobe Flash Builder 4\.metadata\.plugins\)
3. Start FlashBuilder and try to use content-assist, it should work now 
