If you are looking for the decompiler itself, visit https://github.com/jindrapetrik/jpexs-decompiler
+ update 2020: WARNING - support of the decompiler is now VERY LIMITED. There are no active developers. This means we will NOT develop new features and/or fix most of bugs. We left the tracker running in case somebody from community would like to work on it. Sorry for the inconvenience.
List of issues#195 AS2 Decompilation error
Author: 
focus
focusDate created:
Type: bug
Visibility: Everybody
Assigned to:
Labels: AS1/2Obfuscated
State: closed 
Try to select second DoAction in frame 1 of the attached SWF.
I got this there:
_global.=function()
{
/* Error null */
};
as2simple _SecureOpt+domainLock.swf
State: new→opened
version 1.6.5 was released. This should be fixed, try it.
State: opened→upgraded
Yeah, it's fine now!
State: upgraded→closed