I just now finally figured out a workaround for the occasional problem
when using Flex Builder on Vista, where Flex Builder tells you that
another debugger is already running.

The workaround is to add this line to flexbuilder.ini or eclipse.ini
(the name of the ini file depends on whether you installed standalone
Flex Builder or the Eclipse plugin version of Flex Builder):

-Djava.net.preferIPv4Stack=true

That's it. I suspect a bug in Vista -- the first time you debug, I
can clearly see that Flex Builder is closing the socket, but when I
run TCPView, it shows that the IPv6 version of the socket is still
open, and that causes the problem. Adding the above property
definition causes Java to only use IPv4.

- Mike Morearty, Adobe Flex Builder team


--- In flexcoders@yahoogroups.com, Scott Melby <smelby@...> wrote:
>
> Mike -
>
> Thanks so much... you have saved me a ton of rebooting. I was so
> focused on flex builder specific settings related to debug that I
didn't
> notice that setting under general.
>
> Thanks again
> Scott
>
> Mike Morearty wrote:
> >
> > To use Firefox for debugging, you set the Eclipse-wide preference that
> > controls which browser to use for any context where Eclipse needs a
> > browser. It is not a Flex Builder-specific setting.
> >
> > To change it, go to preferences, General, Web Browser.
> >
> > As for the IE problems, I am pretty sure this is caused by changes in
> > IE's security model when Vista's UAC (User Account Control) is turned
> > on. After finishing a debugging session, look for a process called
> > ieuser.exe, and if it exists, kill it, and see if that allows Flex
> > Builder to once again debug. Or, turn off UAC. This is an issue we
> > are aware of; I don't have the bug number handy.
> >
> > - Mike Morearty
> >
> > --- In flexcoders@yahoogroups.com
> > <mailto:flexcoders%40yahoogroups.com>, Scott Melby <smelby@> wrote:
> > >
> > > I have recently setup a new development machine (Vista) and in the
> > > process upgraded to Flex Builder 3 Beta 2. On my old machine the
> > > debugger always used firefox... and all was good :) Now, on this new
> > > machine it is using IE and all is not nearly as good. I am only
> > able to
> > > open the debugger once per reboot of the machine. After that, no
> > matter
> > > how I stopped the debugging session, I am told that another debugger
> > may
> > > be running and that i should close it. I saw an open item for
this in
> > > JIRA, and it all seems to be related to IE (I think). So, I
decided to
> > > switch to debugging in FF. No luck, I can't find anything in the
> > > builder preferences that allows me to tell it which browser to
invoke
> > > for debugging. I tried removing the IE debug flash player, but
now it
> > > just says no debug player can be found and the launches IE without
> > debug
> > > if I choose to continue.
> > > So... can anybody tell me how to force it to debug in FF?
> > >
> > > Any help is appreciated.
> > >
> > > Thanks
> > > Scott
> > >
> >
> >
>