Menu bar issues and resource url?
If unsure about settings I normally double check them against the relevant sandbox -> https://wpmaster.demo.civicrm.org/ (or dmaster for drupal). 

My post upgrade checks for a missing civicrm menu are:


Clear Caches - Twice
Delete all files and directories inside templates_c (Usually located at directory that [civicrm_files] points at. Unless this is overridden in civicrm.settings.php)
Rebuild Menu's


(Note for wordpress the wordpress civicrm admin utilities you mention provides handy links to these, plus more -> https://wordpress.org/plugins/civicrm-admin-utilities/)

Drupal: http://example.com/civicrm/menu/rebuild?reset=1

WordPress: http://example.com/wp-admin/admin.php?page=CiviCRM&amp;q=civicrm%2Fmenu%2Frebuild%3Freset%3D1

Joomla: https://example.com/administrator/?option=com_civicrm&amp;task=civicrm/menu/rebuild?reset=1

(adapted from Joe Murray's answer on How to run triggerRebuild URL)


Check the Browser console for Javascript errors. Extensions (Shoreditch for example) if not kept up-to-date can cause problems if they are overriding files, or expecting specific code that has changed in core. This can lead to the menu not showing. Probably not relevant to you - but for Drupal for example if the setting to combine and compress js files into one is selected then often a completely unrelated error can cause havoc else where. Turn off any aggregation. 


Incorrect resource url:
This warning is triggered if the following file can't be resolved. 
"CiviCRM Resource URL"/packages/jquery/css/images/arrow.png
(Should be located at https://example.com/wp-content/plugins/civicrm/civcirm//packages/jquery/css/images/arrow.png
If you see the "arrows" in you civicrm menu then this is a false positive. If you can't see your menu that doesn't really help sorry. 
From memory there have been some false positives for this warning in a recent install.

Additionally you possibly want to think about upgrading to the latest version of civicrm as there have been a few security releases since your version was released. As well as being insecure, if you are not running the latest version you run the risk that the problem you are having was a core bug that has since been fixed.