After a few retries, turns out that the a process of Flash CS5 was stuck and Flash Builder couldn't call it to rebuild the project.
After killing that process, Flash CS5 was reactivated by FB4 and it rebuilt the project.
At no time during my tries to rebuild did I get any feedback from FB saying that Flash CS5 is not responding or that the code cannot rebuild and this seems like another issue that needs to be fix by Adobe team.
I would love to understand this issue as well. I have had this problem for as long as I have been compiling with eclipse / flash builder. I've always realized it, however, and have just chosen to compile my project in the Flash IDE, which NEVER has a problem building the code and always reflects the current changes, yet much slower.
I don't understand how this could be related to the Flash IDE being stuck in anyway because I do not start my projects in the Flash IDE nor even have it open. I only use the IDE when i need to import assets or when necessary (such as when FB decides not to incorporate my changes).
This is very annoying and I would LOVE to not be dependant on the Flash IDE.
Flash projects in Flash-Builder are relying on the Flash CS5 engine. You cannot create Flash projects without having Flash installed as well. So, when you compile in Flash Builder, you actually run Flash CS5 to compile the project for Flash-Builder. It's quite annoying to need both tools to be running when you're compiling in Flash-Builder, but that's how it works.
The problem starts when Flash CS5 gets stuck (for various reasons) and doesn't do its part. You think you're changes are compiled on the fly, but they are not and any errors you make in the syntax will not be highlighted until Flash CS5 is restarted.
Hope that answered your question.
bona diagnosis, bona curatio
The problem is with the SDK settings selected for the Compiler.
Try going to 'Project' > 'Properties' > 'ActionScript Compiler'.
Now, in the 'Flex SDK section', try changing the SDK. Click on 'Apply'.
This will force FB to rebuild all settings for the project.
You can try again. FB should now have started compiling with latest code changes again.
Please Note: This is not a permanent fix though!
In case the problem re-occurs, you'll need to again perform the steps mentioned above to get FB back on track.
I have the same problem now -
I tried now everything - changing compiler Version - removing all code - restarting
Dunno what else to do - any more ideas?
Except reisntall everything ?
Just off the top of mind, I can think of 2 more things you can try
1. Try publishing your project in debug & release mode & look for changes in both the cases.
2. Ensure that your target folder is same as the folder in which you are checking for changes.
Do inform in case any of that helps!
I'm using Flash Builder 4.6, and I'm getting this problem too. None of these suggestions have helped me so far, even though they all seem plausible.
Has anybody solved this yet?
It is a problem with the way Windows is caching files. Once they are cached and Windows looses track the new files will not replace the old versions with your changes. I rarely saw this until updating to W7. Now it is a huge problem.
I run CleanMgr.exe from Windows tools to clean the system and then rebuild. Fixes the stale files and bad break point issues for me.