Thank you for your quick response!
I did it as you described, but I didnĀ“t get it. I changed the folder and add "...-disabled", but it donĀ“t work.
I checked all plugins from joomla an CB, no results. A few minutes ago I saw that the error disapears on C-Panel and in the plugin folder. I donĀ“t know the exact action I did, but now it works. The error depended on your update feed "Community Builder Updates". I think you use the same feed for the plugin folder to show the version of the plugin. And now it is possible to open the admin modules "Community Builder News" and "Community Builder Updates", what was not possible a hour ago. Maybe you worked on this feed adresses?
Nevertheless, a long day comes to an end and the website ist working.