Read-only & non-realtime mode activated to improve browser performance

Message pops up in my project and I'm unable to delete the nodes as well

Also I read this https://groups.google.com/forum/#!topic/firebase-talk/qLxZCI8i47s

Which states :

If you have a lot of nodes in your Firebase (say thousands), we need to create a new element for each node and modern browsers simply have limitations of how many DOM elements you can add to a page

It says:

To resolve this problem, don't load your Firebase Dashboard at the root of your Firebase, but instead load it lower down in the hierarchy

I do not get what it means

How do I get back to my Realtime Dashboard?