Theme hook MENU_CALLBACK not found I am seeing this error in my logs:

Theme hook MENU_CALLBACK not found


What are the causes? I cannot find this exact phrase in google or d.o. This is an example menu item:

$items['user/%user/integration/%integration'] = array(
    'title' =&gt; 'View An Integration',
    'page callback' =&gt; 'integration_view_page',
    'page arguments' =&gt; array(3),
    'access callback' =&gt; 'is_owner',
    'access arguments' =&gt; array(1, 3),
    'type' =&gt; MENU_CALLBACK,
);


Yes, cleared caches, including menu cache. The actual page appears to load ok.
In my case, this was a mistake on my part. I recently performed a find and replace on my codebase to change all my menu hooks from MENU_LOCAL_TASKS to MENU_CALLBACK.

I clearly did this ignoring case, and also did not check properly as in my template.php, I now had...

$vars['secondary_local_tasks'] = array(
    '#theme' =&gt; 'MENU_CALLBACK',
    '#secondary' =&gt; $vars['tabs']['#secondary'],
);


instead of...

$vars['secondary_local_tasks'] = array(
    '#theme' =&gt; 'menu_local_tasks',
    '#secondary' =&gt; $vars['tabs']['#secondary'],
);


Because it was now called MENU_CALLBACK in caps, it confused me and I was looking in the wrong place. It is only when I went back and diff'd my entire backed up codebase did I notice it.

Lesson Learned: Find &amp; Replace is not always a good idea :)