Hi,
It seems to be sandbox week over on the MG list, as there have been a couple of posts from users having trouble getting up and running in a sandbox. One user has found an issue (see
this thread) which is actually a Reactor problem.
Apparently calling fileExists() on a file outside your sandbox will throw a security exception and this was causing Reactors config.cfc to implode.
I've attached a patch for that file. I don't seem to be able to create a ticket in trac for this though.
Cheers, Chris