This seems like a bug in Flex Builder, however the builder no longer creates the .swf file for any projects (I'm building an AIR app). It did previously however, for some reason it errors out with the message "Initial content not found" (referring to looking for the swf in bin-debug, and not being able to find it).
There are many proposed solutions, such as change the version in the application descriptor from 1.0 to 1.5, however none of these work. I've even imported it into a new project and the swf file is not generated.
Is there anyway to force Flex Builder to generate the swf file?
Thanks.
I actually found this was more of a UI problem, where it is not obvious that there is a problem with the code.
If there are errors in the 'Problems' window (red crosses as opposed to exclamation marks), it will run the old version, not the new version... So while it appears that it is compiling and running the new version, it isn't. Alternatively, as found, it will refuse to rebuild the swf file.
Check the problems window (I think View > Problems in flex builder) and see if there are any errors. I also thought it was caching, but finding the problems window solved my issues.