Description:

AJS.$('#labels-section') resolves to AJS.$(' (None) -section') when used in Main Layout template causing the selector to fail during execution.

To Reproduce:
Add the following code

#if ($userAccessor.hasMembership('confluence-users', $helper.action.remoteUser.name))
#else
    <script type="text/javascript">
    AJS.toInit(function(){                   
       AJS.$('#labels-section').hide(); 
    });
</script>
#end

to Main layout template just after </html> tag. Debug on page refresh and notice "#labels" has been replaced with "(None)".

Expected:

Selector resolves to #labels

Actual:

Selector resolves to (None)

Temporary workaround:
Replace

AJS.$('#labels-section').hide()

with

document.getElementById("labels-section").style.display = "none";

Link to Community post:

https://community.atlassian.com/t5/Confluence-questions/After-upgrade-to-6-7-hiding-certain-selectors-doesn-t-work/qaq-p/726448#M97766