Thanks for your replies. As I said it comes and goes, some days it hits us real bad otherwise we are business as usual.

This is most likely a 'mod/plugin' that is causing your trouble or other sites would have reported it. I would be looking at what commands were being performed in the logs prior to this being triggered. The first step in solving a problem like this is to be able to repeat the condition.

I was going to suggest a method to trap the error and use xdebug to trace through it once you could repeat the condition, but that method might be too advanced of a step for you -- after reading through you threads. If I am wrong please let me know.

Since your a production board, disable any PM mods you are using for now and see if the problem goes away. It would be helpful if you posted what you tried. :)

Thanks for your reply tbworld.

I managed to replicate the error - it only happens when at least one user is viewing their pms.

There are similar complaints posted on other boards about the same issue

http://forums.devshed.com/php-develo...ng-937807.html

Please suggest your method to "trap" the error.

--------------- Added [DATE]1384231175[/DATE] at [TIME]1384231175[/TIME] ---------------

I put $userinfo['values']['do'] == 'updatefolders' instead of $userinfo['action']['do'] == 'updatefolders' and the error message no longer shows.

Thanks to everyone who responded.

Thanks for sending the data, and the reference, it was extremely helpful. If I can simulate this error, I will also report it vbulletin's JIRA.

Good Job! I believe your change is correct, I had to ponder why this did not show in earlier versions.