Maximum of 6 Players Registered for B/C Teams

I created a La Liga team using the editor, and every time I try to start a new career mode and pick my team, it's greyed out. At the bottom, I get the message that there is a “Maximum of 6 Players Registered for B/C Teams," but I have no option to register players anywhere. I've tried everything to get this to work, even going so far as essentially copying the setups for Real Madrid and Barcelona, but still no luck. Anybody have any idea what I need to do to fix this?

Spain has specific squad rules /match day rules 

so those need to be changed if you want to raise the amount -you can make this specific to one team only if you wish

your post is a bit confusing as if a club is greyed out it cannot be selected to be used and you therefore cant get to the stage to register players?

can you read this and post accordingly if you need more info

https://sortitoutsi.net/content/58016/please-read-before-posting 

Thanks so much for the response! And apologies for not being clear enough with my issue.

Here is what I mean by the team I created being greyed out. If you look at Real Iberia CF, it doesn't allow me to proceed with the game.

I went ahead and made the adjustment you suggested, but then I got this:

I even tried adding a few additional match day rules, but they then popped up at the bottom as a reason why I couldn't proceed. And also, when I select this team, I don't have an option to register the players.

Any additional help here would be greatly appreciated. 

 Not sure if I'm doing it wrong in attempting to change the rules for La Liga. I went to Rules > Add Nation Rules > Spain > Divisions. I then added in several divisions and made changes to the rules. I feel like this should work, but I'm doing something wrong along the way.