CustomEvent class issue

What would be the ideal setup for having the file planted in a common .com folder? you mean a com folder that has class files shared among different projects? Now to confuse regarding locations of the class file... There is no copy of the CustomEvent class in the folder that contains the flas that create the swfs, nor in the folder that contains the swfs. Because I have used this CustomEvent class for various projects, I keep a copy of it in my immediate classpath folder.  So based on what you said, there is a chance that the first CustomEvent file in the classpath is what gets seen when I publish rather than the one in the com.path folder if you have an identically named CustomEvent in a default class path (eg, assigned in the advanced actionscript settings panel's source path), the same problem occurs.  that class (in the default class path) will be used instead of the one from the import statement. This same folder contains the "com" folder wherein via the "path" it has another copy of the same class file.  This is because this project has a set of custom-made class files, and the CustomEvent class has been grouped with them in that folder named "com" with the files in the same "path" so that all of the project class files have common location for sharing them with other developers when things change. any same named class files that flash can access are potentially problematic.  to debug your setup, use a different trace() statement in the constructor of the various same-named problematic class files.  that will show you which class file flash is using. While I don't think it matters in this case, there is also a com folder that sits in the main project folder as a repository for the various class files for the whole project.  I say I don't think it matters because it is a folder that is parallel to the folder that contains the flas and another folder that contains the swfs that the fla's publish. it's only irrelevant if flash does not know these files exist.  if any of the files are in its class path, you have a potential problem. One thing that adds to my own confusion is that none of the other class files that live with the CustomEvent class in the com/path folder(s) have this issue... though when those get run it is usually the main file being compiled when it is run, not a saved swf using the CustomEvent class.  that's expected under certain circumstances.  one, there's no name collision.  two, the same-named class files are document class files. and there are possibly other situations. The main file imports the project classes using import com.path.*; Since that local com/path folder sits parallel to the main file (same parent folder), I am imagining it is really using the local com/path versions and not the one intended in the classpath. use the trace suggestion above to see what flash is using. Could it be that the main file is using a different copy of the class file when I test and regardless that it is an identically coded file, it is not the same physical file and things fail as they do? if you use one class file to create an instance, in another class/scope, that instance may no longer be the same class type used in that different scope, even though they're both CustomEvent class types.  ie, you'll get that unable to coerce CustomEvent to CustomEvent error. I still don't understand why the file seems to be looking for the CustomEvent class after it has been published.  When the final product is put in place, it will not have the class files anywhere in sight, so I expect that the swf's should have everything they need published into them. correct, swf files contain the compiled code.  after a swf successfully compiles it doesn't matter where it's located (with respect to the actionscript used) and it doesn't matter what or where the class files are that were used to publish it.  if you publish a swf that has no compile-time errors, running it will trigger no compile-time errors.  but, you may encounter runtime errors.