Setting up multisite network different domains


I have troubles setting up a multisite network. I have bought the domain mapping plugin and multi domains plugin and multisite is activated. Now i have a few problems and i really hope you can help me with it:

Domain mapping does not recognize any sites so they don't show up in the domain mapping tab. Don't know how to add them?

I would like to have 3 different domains for the multisite, when i added them and want to go to the dashboard it gives me a 404 error.

I can add new sites but their should always be something after the slash, don't know why for example " ???".

So at the moment it's not working. Hope someone can help me out.
Thanks a lot.