There have been many cases where attempting to run a form from Forms Builder (purposes of debugging, testing, etc.) will never load the form in the web browser. The page seems to load indefinitely. The URL in the web browser appears to be strange, e.g. http://localhost:51254/X3mJODZxuhNaw9heH7GByuTd1amw3HKIb1pCfGIfIUOKtYXu
To fix this problem, click into the address bar where the URL is and press the Enter key. This will run the form every time.
NOTE: This issue has been seen with 10g (10gR2), 11gR1, and 11gR2 Forms Builders.