After updating to Joomla 3.7.2, the User Manager page is missing the CSS. User Groups, Viewing Access Levels, User Notes, User Note Categories, Fields, Field Groups pages all display fine, only the User Manager is missing the <head> section. When looking at "View Source" for the "Users" page the head section is empty <head>…</head>.
Looking at error.php I see nothing that looks like a PHP error in opening the user management page: Here is a dump of the last couple of entries:
[Mon May 29 15:51:44 2017] [error] [client 66.249.75.28] File does not exist: /mnt/data/vhosts/http://casite-610118.cloudaccess.net/httpdocs/media/plg_jchoptimize/assets/gz, referer: https://911tap.org/557-news-releases/47 ... lbourne-fl
[Mon May 29 15:51:44 2017] [error] [client 66.249.75.30] File does not exist: /mnt/data/vhosts/http://casite-610118.cloudaccess.net/httpdocs/media/plg_jchoptimize/assets/gz, referer: https://911tap.org/557-news-releases/47 ... lbourne-fl
These are related to K2 items and not the User Manager
Nevertheless I uninstalled JCHOptimize, but the problem persists
After I opened and closed the user management page several times, I did see the following in error.php
[Mon May 29 15:52:15 2017] [warn] [client 162.217.174.110] mod_fcgid: stderr: PHP Strict Standards: Only variables should be assigned by reference in /mnt/data/vhosts/http://casite-610118.cloudaccess.net/httpdocs/templates/ae911truth/index.php on line 10
Line 10 in index.php is: $cache = &JFactory::getCache('com_rsform');
If JCHOptimize was the problem, you would think that uninstalling JCHOptomnize would solve the problem, but it didn't.
I use JotCache to manage the cache instead of the native Joomla cache manager. So I updated to the latest version of JotCache 6.0 and made sure all the settings were correct, but this did not make any difference
I thought that perhaps the ModulesAnywhere plugin may have caused the problem, but disabling that had no effect either.
I did create an hidden EasyProfile menu item because that is necessary to inform the Joomla User profile manager that there are extended profile fields that were included with EasyProfile, but again, enabled or disabled makes no difference. Interesting thing, however, I can't uninstall this Component/Module/Plugin without completely breaking the site. That suggests a problem in and of itself; I will look into this.
My only option at this point is to roll back to a backup taken before the Joomla 3.7.2 update after copying all the other changes that have been made during the week.