Roundcube calendar plugin: Call to undefined method rcube_utils::anytodatetime()

[Norbert Veber]

Hi,

I just did a fresh install of roundcube 0.9.5 and the calendar plugin
from roundcubemail-plugins-kolab-3.1.11.  It seems to mostly work, but
if I try to open an email with a meeting invitation, it fails with:

PHP Fatal error:  Call to undefined method rcube_utils::anytodatetime()
in /var/www/webmail/plugins/calendar/calendar.php on line 1871

I also tried the latest git master branch, but same message.

Any idea what would cause that?

Thanks,

Norbert