Which errors do you get in Thunderbird?

I am getting the same error. It is just a PITA to identify where it comes from in the Mozilla-bad-mojo-and-crappy-code world.

I am getting the same error with version 31.0.3 of the addons. Error in console is:

Fehler: ReferenceError: gSOGoConnectorPane is not defined
Quelldatei: chrome://sogo-integrator/content/preferences/preferences-overlay.js
Zeile: 45

I'm also having the same issue with version 31.0.3 of the Connector in Thunderbird 45.1.1 (new install, not an upgrade):

Timestamp: 06/28/2016 04:19:49 PM
Error: ReferenceError: gSOGoConnectorPane is not defined
Source File: chrome://messenger/content/preferences/preferences.xul
Line: 1

Additionally, although I'm able to add remote address books, they never synchronize and I'm never prompted to authenticate to SOGo for the address book (only for the calendars). I don't see any errors in the console that seem related and tell me more than "the specified address book could not be synchronized".

@jeffg:
It never prompts for address books, because SOGo Connector uses Lightning for authentication.
Lightning uses therefore the same account credentials used for calendars.

Double check, that you do not have spaces before or after your address book CardDAV-URL.

I had already removed the non-working address-book, so I can't be sure whether I missed whitespace trimming the CardDAV URL before. While adding the remote address-book again, I found and deleted two contacts (in the SOGo web UI) that somehow had empty names. After re-adding the remote address-book and restarting TB, contact sync worked.

So the SOGo Connector 31.0.3 in Thunderbird 45.1.1 on Fedora 24 may be sensitive to whitespace around the CardDAV URLs, or it may not like CardDAV address-books that contain contacts with blank names. Fixing one or both of those things seems to have gotten CardDAV sync working for me.

Note, though, that I'm still seeing the primary problem as reported by the original poster.

Thunderbird 45.6.0 + integrator 31.0.3

I am getting the same error

Error: ReferenceError: gSOGoConnectorPane is not defined
Source File: chrome://messenger/content/preferences/preferences.xul
Line: 1

The list of contact categories is empty now an the buttons for add, edit and remove do not work anymore.

Fixed, test: http://packages.inverse.ca/SOGo/thunderbird/nightly/

Release coming up next week.