well I got a bit further, I can now create a slave site into
site_url/multisites/site_id, with the symbolic links present, a had to do a fresh joomla install for the master site. But when I try to log into the slave sites administrator I get an error message saying, that I don't have permission to do so. How can I log into the back-end of the slave site?
I tried to create a slave site using a template with copy folders instead of symbolic links, that looked to work until I noticed that within the back-end not all menus and buttons are working the global configuration looked strange, all settings where shown on the first page and most of all the multisites folder is created over and over again something like:
multisites/site_id/multisites/site_id/multisites/site_id............. I got down to like 20 folders!!!
I'm still in contact with the provider, I've tried setting multisites up with a different webprovider, worked fine there, so I guess there might still be an issue with the server settings.
When I create a slave site no matter if it's a fresh site or according to a template, I still have to change the permission settings for the created files and folders, otherwise I can't install new templates, components etc.
I just noticed that I still can't create a fresh slave site I get an error message "403 Forbidden" when I try to open the slave site, the only files and folders created are:
1 folder: "cache"
and
1 file: "config_multisites.php"
nothing else!