Installing plugins currently broken

[DigiAngel]

Topic says it...per http://plugins.roundcube.net/ and following the instructions:

Loading composer repositories with package information
Initializing PEAR repository http://pear.php.net

  [RuntimeException]
  Failed to execute git clone --mirror 'https://git.kolab.org/diffusion/PNL/php-net_ldap.git'; '/root/.composer/cache/vcs/https---git.kolab.org-diffusion-PNL-php-net-ldap.git/'
  Cloning into bare repository '/root/.composer/cache/vcs/https---git.kolab.org-diffusion-PNL-php-net-ldap.git'...
  fatal: unable to access 'https://git.kolab.org/diffusion/PNL/php-net_ldap.git/';: server certificate verification failed. CAfile: /etc/ssl/certs/ca-certificates.crt CRLfile: none

install [--prefer-source] [--prefer-dist] [--dry-run] [--dev] [--no-dev] [--no-plugins] [--no-custom-installers] [--no-autoloader] [--no-scripts] [--no-progress] [-v|vv|vvv|--verbose] [-o|--optimize-autoloader] [-a|--classmap-authoritative] [--ignore-platform-reqs] [--] [<packages>]...

removing that entry allows me to go forward

I added the below plugins:

"roundcube/filters": "dev-master"
"roundcube/carddav": "dev-master"

and ran php composer.phar install.  Now all I get is a blank screen when I log into roundcube.  Currently carddav completely breaks roundcube altogether.  Enabling any type of filter on the Filters tab gives a server error.  Continuing to troubleshoot..