G Suite Installation Error Leading to Forbidden Screen on Authentication

[javacodemonkey]

I have recently been tasked with setting up the G Suite add on for our WHMCS set up and I have been following the instructions as thoroughly as possible (link provided below).  I have already set up the OAuth project and I have gotten to the point where I am setting up the product under the group under Setup > products/services > products/services.  When I attempt to use my OAuth client secret and ID to  Grant access to Google Account, I am redirected to a  Forbidden page (also listed below) in the module settings screen.  I have checked my path (which is configured correctly), file permissions (all set to 777), and my Google Project (which has the logs showing that the authorization was granted).  I've been working on this non-stop since yesterday and would greatly appreciate any advice or direction out there.

 

Forbidden

You don't have permission to access this resource.

Additionally, a 403 Forbidden error was encountered while trying to use an ErrorDocument to handle the request.

https://www.docs.modulesgarden.com/G_Suite_For_WHMCS

[javacodemonkey]

For those that have a similar message they encounter, it appears the WHMCS site causes this issue if updates are not made consistently.  In fact, any page where a submit button is pressed causes the page to error out with the same message.  Updating the site to the newest version causes my whole site to crash and I'm working to find a solution.  At least I'm somewhere further than before.

[javacodemonkey]

After running the updates on the site and copying the files over to another domain, I'm seeing that the init.php file is causing a redirect constantly.  The whole file is encrypted, so it's impossible to determine how to correct it (along with every other file (thanks WHMCS for doing this by convention)).  Found this was the file forcing the redirects by replacing the index.php, clientarea.php, and login.php files that continuously redirect.  Still hunting for the solution that allows this to work.