Downloading and installing K2 last night seems to have coincided with a major HTTP 500 error affecting Menu Manager in the Joomla backend.

I can no longer modify or add menu items to the only menu on my site, without it throwing up this error. I have tried all the familiar solutions (renaming .htaccess, checking permissions) but to no avail. I do have AceSEF running, could this be the reason?

I would be grateful for any help you can give.

Simon

Did you back up before installing or recently?
Are you running the 2.5 on j1.5 or j1.7 as it works on both?
Have you tried turning sef off and see if the problem resolves

Yes, luckily I have a recent backup I can roll back to.

I'm running Joomla 1.7

I've tried disabling sef and unfortunately the problem still occurs.

I haven't heard of this error before, could be something else or just a faulty install

Here's the contents of jcontroller.log.php, in case they offer assistance.

#<?php die('Forbidden.'); ?>
#Date: 2011-10-18 12:48:12 UTC
#Software: Joomla Platform 11.2.0 Stable+Modified [ Omar ] 27-Jul-2011 00:00 GMT

#Fields: date time priority clientip category message
2011-10-18 12:48:12 INFO 2.??.???.??? - Holding edit ID com_categories.edit.category.2 Array ( [0] => 2 )
2011-10-18 12:48:13 INFO 2.??.???.??? - Checking edit ID com_categories.edit.category.2: 1 Array ( [0] => 2 )
2011-10-18 12:48:26 INFO 2.??.???.??? - Checking edit ID com_categories.edit.category.2: 1 Array ( [0] => 2 )
2011-10-18 12:48:26 INFO 2.??.???.??? - Releasing edit ID com_categories.edit.category.2 Array ( )
2011-10-18 13:36:03 INFO 2.??.???.??? - Holding edit ID com_menus.edit.item.104 Array ( [0] => 104 )
2011-10-18 13:36:06 INFO 2.??.???.??? - Checking edit ID com_menus.edit.item.104: 1 Array ( [0] => 104 )