We have released a new version of the plugins that includes a number of fixes and upgrades. The file paths in the calendar plugin were updated to fix the problems occuring on installations where the Roundcube library is located outside of the Roundcube directory; the calendar event attendee autocomplete options were improved; and the popup UI was updated to work properly on the elastic-based skins.
The framework plugin was upgraded to fix the problems with language switching. We have also verified and made sure that the plugins work properly with the latest version of Roundcube (1.4.3.)
We encourage you to upgrade to the new version of the Roundcube Plus plugins to improve your user experience.