...with Norton Internet Security enabled.

Is this a bug? Will it be fixed? I'm able to edit posts with NIS switched on, but sending new messages won't work.

I think they covered this error (not a bug) in the Bug Reports section:

https://ubbdev.com/threads/php/...ew=collapsed&sb=5&o=&fpart=1

Lisa_P does a wonderfull job of describing how to adjust Norton's settings. []/forum/images/icons/smile.gif[/]

OK, sorted. []/forum/images/icons/smile.gif[/]