In trying to Activate access restrictions to User Role Editor for single site administrator I get a notice that says
The site is experiencing technical difficulties. Please check your site admin email inbox for instructions.
Looking in the consoles this appears
settings.js?ver=5.2.3:17 Uncaught TypeError: jQuery(...).button is not a function
at HTMLDocument.<anonymous> (settings.js?ver=5.2.3:17)
The logs show this
[Wed Sep 18 13:01:30.825495 2019] [proxy_fcgi:error] [pid 3130] [client 68.173.117.192:55744] AH01071: Got error 'PHP message: PHP Fatal error: Uncaught Error: Call to undefined method URE_Lib_Pro::filter_existing_caps_input() in /var/www/wordpress/wp-content/plugins/user-role-editor-pro/pro/includes/classes/settings-pro.php:192
Thoughts and ideas on how to resolve. Thanks.