I'm facing this problem again and again, but can't find any solution (except mine, which is not as a good one I guess).
Don't know why, sometimes Flex Builder executes old source codes after making changes. While debugging I see how it steps through a source (e.g. changing local variables) which does not exist (even if I delete all that block or function).
My way to solve that is to delete the project (backing up the source codes of course) and create a new one, add the backed up sources to the project and rebuild. It starts to work as it should work, but this way is not as comfortable, especially if sources are on a remote machine and you need to configure .net back-end.
Anyone knows how to solve?
I ran into this problem as well. What you can do is this:
- Execute the clean command in Flex builder.
- Close the project with the problem.
- Go to your project folder in windows explorer / Finder etc.
- Delete the debug/release folder in the filesystem.
- Reopen the project and rebuild.
Problem should be solved after that.
Try Project->Clean to dump everything and rebuild from scratch.
Yes I forgot to say - that doesn't help too.. Usually first thing I try in that case is to switch off Automatic Build, Clean the project and Build All again.. The same thing.
My guess is that maybe Builder is not able somehow to rebuild remote SWF and runs the old one.
Check your problems tab, if there is any error it will launch the last build that was successful.
If all the problems are solved and it still happens than preform project cleanup as RickDT states.
Normally when I update from SVN and the main.swf got overwritten I have to 1: revert main.swf and 2:perform project cleanup for it to launch normally again :)
Took me a damn while to figure out tho.
I have lived with this annoying problem for a while now. This begins to happen every few days. The best solution i have found is to (a) cleanup (b) change the default Web browser under Windows->Properties. I switch between FF & chrome. Please let me know if you have a better solution.
UPDATE: I found out that I was improperly using SWCs and actually compiling parts of my project into them. When I did this Flash Builder assumed I wanted to use the SWC classes instead. I did a blog post about it here: http://inchwormstudio.com/blog/flash-builder-flash-workflow-and-the-danger-of-careless-swcs/
ORIGINAL: I've been running into this as well lately. So far Gorro's solution has been the only one that works for me. Backup to SVN or whatever you use. Delete the project in flex builder including the files on your HD. Checkout the project again and rebuild. It's a very annoying bug especially since the first time I ran into it I almost had a heart attack. It kinda throws the safety net of SVN out the window when you realize that your source is fine but the compiler is just doing what it pleases. I should point out that this occurs in Flash Builder as well as Flex Builder.
I deleted the myProject.swf from the HTML-template directory... seemed to do the trick for me then and there.
来源：https://stackoverflow.com/questions/290768/flex-builder-3-executing-old-source-codes