Update There is a new solution at Still getting General Failure messages in Firefox
Original Post
This problem occurs when you click on a link in Outlook and the page opens in Firefox but also creates an error message along the lines of:
General Failure. The URL was:
“http://www.devblog.co.uk”. The system cannot find the file specified.
I think that this problem only occurs in Outlook 2007 but I could be wrong. Anyway, the problem appears on both XP and Vista and in both cases the same registry fix will cure the problem. Usual advice: back up the registry and important data and if it all goes wrong, moan to someone else!
Go to “Start > Run” and Enter “Regedit”. Or in vista I think you can just type “Regedit” in the box at the bottom (I can’t be more specific, I left my Vista laptop at work). When you’ve got regedit open head to the following path:
HKEY_CLASSES_ROOT\FirefoxURL\shell\open\ddeexec
Open the key “Default” which should have the value of “”%1″,,0,0,,,,”. Delete the string of crap and save it then exit Regedit. This will stop the warnings from popping up.
A quick warning though – If you tend to switch the Default Browser between Firefox and IE (for banking reasons or website testing such as myself) then when you switch back to FF the problem will come back and you’ll have to edit the registry again.
I'm a web developer based in the East Midlands, UK and if I keep up the current rate, I might have developed 3 million sites by the time I retire