problems with upgrading from 3.0 to 3.1

[pigsound]

i deleted it and it got rebuild, but now i get this messages:

Warning: mkdir() [function.mkdir]: Keine Berechtigung in /cluster/www/myhomepage.xy/GetSimple_3.0/admin/inc/common.php on line 76

Notice: Trying to get property of non-object in /cluster/myhomepage.xy/GetSimple_3.0/admin/inc/plugin_functions.php on line 75

i notice that for every plugin i deactivate, another notice like the one above is thrown.

the rebuild "plugins.xml" looks like this:

Code:

<?xml version="1.0" encoding="UTF-8"?>
<channel><item><plugin><![CDATA[user-managment.php]]></plugin><enabled><![CDATA[false]]></enabled></item><item><plugin><![CDATA[InnovationPlugin.php]]></plugin><enabled><![CDATA[true]]></enabled></item><item><plugin><![CDATA[anonymous_data.php]]></plugin><enabled><![CDATA[true]]></enabled></item></channel>