Ok. I could solve this problem.
First of all, i deleted the wrong SOLR Directory.
Wrong Directory = /var/local/xwiki/solr
Right Directory = /var/local/xwiki/cache/solr
To solve the problem with Server not responsible i used the Web Developer Tools and see that xwiki try to connect via http for AJAX (see https://forum.xwiki.org/t/initial-save-returns-failed-to-save-the-page-reason-server-not-responding/7774/5.
To change xwiki.cfg:xwiki.url.protocol=https make no differences.
I had to follow https://www.xwiki.org/xwiki/bin/view/Documentation/AdminGuide/Installation/InstallationWAR/InstallationTomcat/ - Configuring tomcat for https to get rid of this problem.