Perhaps you needed to upgrade PHP on your Servers too. I needed to do this, because i wanted to use tine20.org with my local thunderbird.
I thought nothing easier than that and contacted my server maintainer, the guys @hosteurope.de did a great job and upgraded php very fast – thanks guys.
After some time i found out knowledgetree is out of order and the odysee began.
After digging into the code and having used google heavily i found a solution:
Go to config/dmsDefaults.php and transform
error_reporting(E_ALL & ~E_NOTICE);
error_reporting(E_ALL & ~E_NOTICE & ~E_WARNING & ~E_DEPRECATED);
This way all deprecated warnings and general warnings are suppressed, not the way to go for development, but usefull to know finally.
Some minutes later i also found a related forum post http://forums.knowledgetree.org/viewtopic.php?f=6&t=19647