I see you quoted my previous reply...
I don't want to sound rude but yet I would say that a little attention to the content of posts or replies helps a lot of times.
First I would say that I did not post (in this thread) any modified plugin but just I showed a solution on how a file in this plugin can be modified, being sure that everything was obvious to anyone with minimal PHP skills.
The
purpose of the change I indicated
is only to remove the nags (as you can see in the images I posted) and not to replace going through all the steps required to activate the plugin.
My modification will only work after you install and activate the plugin.
Seeing the screenshots it is obvious that
you haven't gone through the whole WPML activation process yet.
Although I don't know German, I see that you are asked for a license key which is not OK - uninstall the version you are trying to install and try the version posted by
jamesnarry
Only after you have activated WPML do the modification I suggested...
Good luck!!!
P.S. From the first screenshot it's clear that you have not (yet) made the change