Notice: Trying to get property of non-object in node_page_title() (Zeile 2108 von /var/www/modules/node/node.module).

Please provide some more background information for this issue:
- did this happen immediately after installing or upgrading, not after enabling some contrib. modules?
- is this on a brand new 7.15 installation, or an upgrade from a previous drupal version? (if so, from which version?)
- when you try to install a brand new 7.15 on the same server, without enabling any extra contrib. modules, do you get the same problem?
- does your watchdog log show any other errors around the same time this occurred?

(please do not assign issues to yourself unless you are going to work on a fix for it yourself)

ok, thanks for the background information.
(no need to apologize, I am just informing you, tons of people does this, so it is not intuitive what that assignment is for :-) )

This means that this issue is not specific to 7.15, so therefore I move it onto the 7.x-dev branch for further discussion.

This is not necessarily a core bug either, though.
Check out this issue which might have some relevance for the troubleshooting:
#1187776: Use with Menu Block causes PHP notice and active trail problems
(if it helps, please report back here)

This is the code I use to fix the issue. It simply checks to see that the 'title' value exists before trying to send it back. Fixes the problem for me until I update the core version I am running

node.module - starts line 2104

/**
 * Title callback.
 */

function node_page_title($node) {
  return $node->title;
}

with

/**
 * Title callback.
 */
function node_page_title($node) {
  if (property_exists($node, 'title')) return $node->title;
}

The fix I found (not a core hack, though I do agree with core dealing with this better, as illustrated above) was to remove some database corruption from my menu_links table.

http://drupal.org/node/429910#comment-6641288

This may work for someone. Issue found in 7.12 FWIW. I needed to remove existing problems before feeling comfortable to upgrade.

#6 did not fix it for me. Will do the hack from #4 for now :(

This is a duplicate of #1697570: _menu_load_objects() is not always called when building menu trees

Also Notice when changing Settings, Modules

Guys,

You can achieve the same goal without hacking the core.

/**
 * Implements hook_menu_alter
 */
function [YOUR MODULE]_menu_alter(&$items) {
  $items['node/%node']['title callback'] = '[YOUR MODULE]_page_title';
}

/**
 * Helper function to replace node_page_title
 */
function [YOUR MODULE]_page_title($node) {
  if (!$node) {
    return '';
  }

  if (is_numeric($node)) {
    $node = node_load($node);
  }
  return !empty($node->title) ? $node->title : '';
}

Has anyone tried #9

@leisurman I haven't tried it personally but #9 looks like a good temporary solution.

Thanks berliner,
Does the #9 code go into template.php or create a custom module with it.

I tried it in a module but got an error. I did change the [YOUR MODULE].

system non_object module enabled.
3298 13/Mar 09:45 error php EntityMalformedException: Missing bundle property on entity of type node. in entity_extract_ids() (line 7880 of /var/www/html/upgrade2a/includes/common.inc).

#9 worked for me. My issue was being caused by a custom module I created, so I just added the code from #9, to my module. Worked like a charm!

Yep-yep, #1709914-9: Notice: Trying to get property of non-object in node_page_title() (Zeile 2108 von /var/www/modules/node/node.module). (#9 above) workaround above makes sense and does work.

According to #1697570: _menu_load_objects() is not always called when building menu trees, the issue occurs when we try to build a menu twice (like for unequal displays in two different blocks). The specific issue is that menu translation receives just an integer nid rather than the expected $node object on second+ passes.

If core is ever patched to address this issue, then #9s custom module code won't be necessary anymore.