You don't have permission to access / on this server/ on https://127.0.0.1

HI,
I have a very hard time setting up owncloud so that i can use it with ip adresses. Even https://127.0.0.1 gives me an error.
the only way that works is by using a domain instead of ip, but i really need to use the ip.
even adding them to config.php doesn't work....

Depends a bit how you configured your webserver's virtual hosts. Normally the first VirtualHost is used in Apache if none of the others match (with ServerName). More on this with a number of examples:
https://httpd.apache.org/docs/2.4/vhosts/examples.html