[otrs] Core.UI.InitCheckboxSelection is not a function after upgarde to 3.2.8

Hello list, after upgrading a pretty old otrs instance to 3.2.8 ( i had to go from 2.4.9 -> 3.0.20 -> 3.1.17 -> 3.2.8) i get a message box when ever i select something from the "Tickets" menu. After that i can not click on any buttons on the web page any more. Every thing else seems to work fine. i saw some other people with the same error, but could not find a solution: - http://forums.otterhub.org/viewtopic.php?f=35&t=21065 - http://forums.otterhub.org/viewtopic.php?f=31&t=19553 Any help would be highly appreciated! Thank you very much. With best regards, moe