From your additional information on thread www.joomlapolis.com/forum/153-professional-member-support/228673-cb-a-cbsubs#259621:

tmoran wrote: Hi,

I started a topic in CBSubs 4 days ago and haven't received any response...
www.joomlapolis.com/forum/277-cbsubs-gpl-support/228611-installation-issues

I'm hoping I can get some feedback by re-posting in the professional forum.

Whenever I go to CB Paid Subscriptions > Settings I cannot Save, Apply or Close. All I get is:
403 Forbidden - Access to this resource on the server is denied!

I have since upgraded to CB 2.0.6 running J 3.3.6 and still have the same issue. I have installed & enabled every CB 2.0 plugin and all CB Subs plugins (4.0.0-rc.1 .)

If I try to access Paid Subscriptions > Payment Gateways all I get is this:
Fatal error: Cannot instantiate abstract class cbpaidGatewayAccount in <span>/</span>home<span>/</span>thc/public_html/components/com_comprofiler/plugin/user/plug_cbpaidsubscriptions/models/table/cbpaidInstanciator.php on line 137

There were numerous other error reports prior to upgrading (see previous post) but these no longer appear with error reporting set to max.

I'm not sure if this is a CB issue or a problem with CBSubs... Can someone PLEASE help! If someone can PM me I can provide admin access to the site.

We are currently looking into this issue with the credentials provided in your support ticket opened 20 minutes ago, and will reply to the ticket with updated information.

Also following up here ...

Huge apology for missing this thread.

We found the issue and removed a bad row in your cbsubs gateway table and I also updated your installation with latest CBSubs 4.0 nightly build.

Things seem to be working now - please verify.