[kh99]

Originally Posted by ForceHSS

eval is caused by a custom plugin disable all plugins and test on default skin enable one at a time until you find the one that is making the error

Often that's true, except in this case if you look at the source code you'll see that line 688 of includes/functions_editor.php (in version 3.8.6 PL1) is this:

PHP Code:

    eval('$messagearea = "' . fetch_template($editor_template_name) . '";'); 


which looks to me like the problem is in a template, so that's why I suggested checking the editor templates.

It is possible a mod is trying to change the cached template, so disabling mods *would* be something to try.