Infinite message “Loading…” with Kolab Plugin

[safi]

We are trying to install Roundcube 1.1.4 on an Ubuntu 14.04 with LAMP. The implementation performs flawlessly with the back-end email server, even on very large email folders.  Thanks to the creators of such a great product. However adding kolab/calendar 3.2.8 breaks Roundcube and clicking on an email to view it shows message "Loading..." till it times out. The IMAP log file is normal but the errors log file show "PHP Fatal error:  Class 'Sabre\VObject\Property\Text' not found in ...libvcalendar.php on line 1386. According to this post http://lists.kolab.org/pipermail/devel/2016-January/015407.html, Ubuntu lacks the needed version of php-sabre-vobject.

Would appreciate any input from the community who faced a similar problem and a workaround if any.

Thanks