This is strange and I am not sure if anybody else had the same experience . Today morning when I opened Flex builder to continue my work on an AIR application after couple of builds and runs the application stopped launching. I tried several times and was confused as to what could have happened to the application that was running perfectly last time. Then I tried debugging it only to find a prompt which says -“Process terminated without establishing connection to debugger”.
To find a fix to this I turned to the only hope for all developers GOOGLE and found that there was a similar issue reported to the Adobe BugList http://tinyurl.com/d3ws5h but this issue was reported only for MAC machines and mine was windows.
It suddenly struck my mind that it was after the application threw a runtime error all this started and curiously I opened the taskmanger and BINGO!! here it is adl.exe is still running. I ended adl process in the task manager and everything was to normal. The adl.exe which is located inside the bin folder under sdk folder of the Adobe Flex installation directory is the factor which launches your AIR application (something like C:\Adobe\Flex Builder 3\sdks\3.4.0\bin).
Now what could have happened is when the application threw a run time exception even though the application was closed the instance of adl.exe was still running in the system which prevented the next launch. This might not be proper fix but surely which can get you out of trouble. I wonder if anybody else had faced the same problem if yes, do let me know if you had some other way to fix this.