Multisite after correct installation dont active

Hello, with my hoster we test more times but the multisite function dont will open?
Its maybe a plugin where blogged them or what is? I have deactivate all and make all perfect, too. My Hoster help me more times and they dont know what is the problem.

I have displayed other options for network installation there. There is no option for Subdomain etc.

There is written now only: Warning: An existing WordPress network was found.

Please complete the setup steps. To create a new network, you must clear or remove the network database tables.

There is no WEBSITES appeared? Its the same more? My hoster dont know that, too.

Please help i cant find other manual! I will upload what i mean but here is no option.

The page I need help with: [log in to see the link]