Your blank page is likely associated with the fatal query error you attached in your previous post. It has nothing to do with CB, but is in relation to K2. Please contact them for further assistance. Likely a Joomla system plugin designed to keep users in sync for K2. The query error points to "articlesanywhere", not sure what this system plugin does but please try disabling (this is a step we ask within Help Us Help You, please re-review).

CB Triggers routes Joomla triggers to CB, it's possible one of those routes is causing problems or that one of the system plugins installed is trying to act on one of Joomlas triggers which CB Triggers doesn't quite understand what to do with it.

CB Triggers is not required and is only needed for a few plugins. Please try disabling articlesanywhere however or any plugin related to K2 with CB Triggers enabled.. the issue is you've a fatal query error that's trying to query K2 database, but you do not have K2 installed. CB Triggers is simply loading whatever is making that query (as it's designed to do, so CB plugins can act on those triggers).

With "maximum" I get the following errors when I go to register (see in the picture)

Reviewing the error message it would seam you've a bug in your GJ language file, please check line 1 as it states. Please also try disabling this language plugin to see if issue resolves.