Antwort #1 am: 14. Mai 2014, 17:33:03
According to the documentation (unfortunately for you in German) you need to do 3 steps:
1) Make sure your webserver has mod_rewrite enabled
2) Activate SEO URLs (<- you did this)
3) Rename in your shop root folder the file _.htaccess to .htaccess
3.1) IF your shop is installed in a subfolder, you need to edit .htaccess file! The line "RewriteBase /" needs to become modified like documented in this file.
If you did all this and it is still failing, you need to ask somebody with deeper knowledge about this software.