Ok, digged deeper, as usual:

Authorize.net has a well-formed certificate for their test-server, but an incomplete certificate for their production server! (and production server gets a less good grade):

www.ssllabs.com/ssltest/analyze.html?d=test.authorize.net&hideResults=on

www.ssllabs.com/ssltest/analyze.html?d=secure.authorize.net&hideResults=on

And indeed the production server uses a very recent root certificate. So that host is not completely up to date would explain it.

We have a "backup" root certificate bundle in CB for such cases, I have just updated it too, and built a nightly CB release.

I have tested if the production server of authorize.net validates with the new CB backup root certificates chain and it now does.

So can you please upgrade CB (keep CBSubs at the latest nightly, just upgrade CB) to latest nightly release and re-test ?

Ok, great, now your https accesses to the new authorize.net servers with new certificates work! And double-transactions are detected correctly (well, displayed twice, but that's minor).

The "1048 column 'subid' cannot be null" (that appeared on your site 5 months ago here: www.joomlapolis.com/forum/153-professional-member-support/239919-error-message-after-payment-1048-column-subid-cannot-be-null ) is a different issue. Not even sure that it is inside CBSubs, as that looks like a MySql query error, and no CBSubs tables have a "subid" column.

Could you please do 2 things:

1. Check database structure in: Community Builder Tools: Check all 3:

- Check Community Builder Database
- Check Community Builder User Fields Database
- Check Community Builder Plugin Database

And repair if any structure is not up-to-date.

2. Turn Site Debug to ON in Joomla Configuration and try re-triggering the error, that should give more information.

There is a second thing that makes me think that the error is outside CBSubs: There is no Error log for this error in your "History" error-log of CBSubs.

Maybe you have some other plugins or auto-actions with a column "subid" in a database ?