I have a strange problem. If I enable node_view in page_manager everything works as expected and the node layout is according to my settings. If I then do a menu cache clear node_view is not used anymore and my node layout is as without node_view. If I do a
shortly after activating node_view the array contains the normal values. Looking into the db the variable
returns 0 as it should be. After the menu cache clear the function in (1) returns an empty array whereas the variable in (2) remains 0. Also the node_view page stays active inside the page_manager UI. If I deactivate and activate node_view everything works again until I refresh the menu cache again. So this seems to be an infinite loop for me: Everytime I do a menu cache flush I have to deactivate/activate node_view.
I don't know how long this problem exists, but I observed changes in my node layout also last year. I am using Drupal commons, so maybe the problem is related to this, since commons throws in a lot of modules and perhaps something overwrites node_view (panelizer is disabled on the specific nodes).
If I look into the code of the module, there should be a message
drupal_set_message(t('Page manager module is unable to enable node/%node because some other module already has overridden with %callback.', array('%callback' => $callback)), 'error');
if node_view is overridden, but there is simply nothing in dblog. I am really stuck here...
Does anyone have an idea what could be wrong or what I could do to find the reason for this behaviour?