undefined function can mean two things : the author of the script had a typo/used a wrong function (or a deprecated one), or the function declaration was not included.
perhaps you would like to clean install the phpbb files. dss_rand is not a PHP function.
yea just delete the whole forums and reinstall again...
dss_rand() may not be a PHP function, but it is a phpBB function.
It's defined in includes/functions.php and referenced 8 times throughout the phpBB code. It looks like includes/functions.php is included in common.php, which is in turn included in most of the main phpBB files.
The easy way out would be to re-install the whole forum. But, what's the fun in that?
A possible problem arises from the fact that bbcode.php (the file that incurred the error) does not directly include functions.php (the file that contains the defined function). If you're using a stock install of phpBB, then this shouldn't be a problem. But, if you've tampered with the files (install a mod, or tried to write some mods yourself) you could have accidentally caused this.
What file did you actually open in your browser when the error occurred? The function in bbcode.php that uses dss_rand() (make_bbcode_uid) is only referenced in five other files - posting.php, privmsg.php, admin/admin_users.php, includes/function_post.php, andincludes/usercp_register.php. So the trail of the error probably leads back to one of these files, or whatever file you attempted to access if its something else.
Ah, dont worry guys, its fixed.
Someone at the phpBB forums helped me out.