Everything I find on this topic is related to CLI debugging, I am not doing CLI debugging.
When I attempt to debug PHP I get the following error message in PHPStorm:
Cannot accept external Xdebug connection: Cannot evaluate expression 'isset($_SERVER['PHP_IDE_CONFIG'])'
I am on Win 7 with Version 4.0.2 of PHPStorm.
I assume I just have something configured incorrectly, but I have tried everything to fix it with no luck, and "the google" hasn't returned anything very helpful with this issue.