I tried to upgrade from CB 1.9.1 to the 2.0.14. Initially I got a lot of errors (which I didn't copy, unfortunately) and CB disappeared from my admin menu, and it looks like some items were upgraded (Community Builder, Community Builder Library and Community Builder System Plugin report 2.0.14), whereas the modules are mostly reporting version 1.8.1.
When I tried to install again, or try to access CB via the CB Admin Menu (which is still there), I get these error messages:
Warning: require_once(/Applications/XAMPP/xamppfiles/htdocs/clients/mkl/components/com_uddeim/uddeimlib31.php): failed to <span>open</span> stream: No such file or directory in /Applications/XAMPP/xamppfiles/htdocs/test/components/com_comprofiler/plugin/user/plug_uddeimprofilelink/pms.uddeim.profilelink.php on line 34
Fatal error: require_once(): Failed opening required '/Applications/XAMPP/xamppfiles/htdocs/clients/mkl/components/com_uddeim/uddeimlib31.php' (include_path='.:/Applications/XAMPP/xamppfiles/lib/php') in /Applications/XAMPP/xamppfiles/htdocs/testl/components/com_comprofiler/plugin/user/plug_uddeimprofilelink/pms.uddeim.profilelink.php on line 34
I did try to upgrade UdddeIM after the fact, but that didn't fix anything. I have backups and can start afresh, if the problem lies in the order in which things need to be updated and installed.
I am running Joomla! 3.5.1 and use GroupJive, Kunena and a few other of your plugins.
I'm going to answer my own question, in case it helps anyone else: You need to uninstall UddeIM and the CB plugins, then the upgrade works without any problems.