Error "You are not authorized to view this resource" and CB System Plugin

Folks,

We have implemented a mobile app solution from GoNative, which essentially wraps the Web site in a viewer. In that app, when a member logs in and checks the "remember me" checkbox, then revisits the site later, they get an onscreen error from the Web site "You are not authorized to view this resource." It is unclear what exactly they are not authorized to view, since the page that displays with that message is the member home page, and it appears that all member functions are correctly accessible, and that error message gives no additional info as to what caused it to appear.

Here's the weird thing: if we disable the plugin "Community Builder System plugin," users no longer get this error. (But our Joomla admin screen warns us that with the plugin disabled, CB will not function properly -- and yet, CB seems to work.)

So, A) can we leave CB System plugin disabled, and if so, what impact might that have? is there some way (besides random trial and error) to determine what auth conflict was causing the initial message?

Thanks in advance for the help.

-Brian Wold, Web Consultant

--- SYSTEM INFO ---

PHP Built On Linux box1160.bluehost.com 3.10.0-614.10.2.lve1.4.50.el6h.x86_64 #1 SMP Mon May 22 17:31:11 EDT 2017 x86_64
Database Version 5.6.32-78.1
Database Collation latin1_swedish_ci
Database Connection Collation utf8mb4_general_ci
PHP Version 5.6.32
Web Server Apache
WebServer to PHP Interface cgi-fcgi
Joomla! Version Joomla! 3.8.3 Stable [ Amani ] 12-December-2017 15:00 GMT
Joomla! Platform Version Joomla Platform 13.1.0 Stable [ Curiosity ] 24-Apr-2013 00:00 GMT
User Agent Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:57.0) Gecko/20100101 Firefox/57.0

The system plugin redirects from Joomla com_users components. It also corrects some other issues with missing GET/POST variables that Joomla doesn't add from menu URLs. CB will not function properly without that system plugin. It maybe just the com_users redirect behavior causing your issue which you can disable in the plugins parameters. In short it's trying to send them somewhere they don't have permission to go before the remember me cookie has been processed by Joomla and is why that error gets queued into Joomlas message queue.