[opencms-dev] edit interface is not shown up after login

[Manuel Oetiker]

Hi

I have migrated a opencms installation from a windows to a linux side. 
( tomcat7, apache24, postgresql, opencms 9.0.1)

the website runs ok but after I login on http://..../system/login the interface for editing the
page does not show up. it jumps back to the normal webside. 

any hint where I could look for the problem... ( in the opencms.log is nothing except the successful
login )

hope someone has a idea.

thanks Manuel