Not sure if it's exactly the same thing, certainly the same symptoms, but there's a known issue if you're using modules as part of your project:
https://bugs.adobe.com/jira/browse/FB-12298 --- In flexcoders@yahoogroups.com, "okie_174" <rj...@...> wrote: > > Yesterday I found that Flex Builder (v3) was no longer reporting compiler > errors when compiling. It is reporting warnings but no errors. I purposely > introduced errors and it will build the project and then present a blank > screen. I have looked to see if there's some sort of setting I made by > mistake to make this happen but can't find anything. I re-installed Felx > Builder but it didn't help. > > Anyone know why Flex Builder would suddenly stop reporting compiler errors? >
