[imp] Turba not working after upgrading horde to 3.1.1

[Alan Kong]

Hi,

My turba wouldn't work after horde was upgraded from 3.0.6 to 3.1.1. 
Version of turba is: 2.0.4. The following was observed in horde.log:

May 18 16:51:42 HORDE [emergency] [horde] Horde_Block_turba_tree_menu 
not found. [on line 235 of "/local/WWW/horde/services/portal/sidebar.php"]


Could you please help in solving the problem.

Thank you.

Regards
Alan