BoltConnectionError in Academy

I'm in the middle of a GraphAcademy course.
I get "BoltConnectionError No connection found, did you connect to Neo4j?" in the sandbox.

I have no idea what this means, and I don't recall connecting to anything?

I'm afraid this isn't very helpful or useful for a learner.
There is no indication of what to do to get out of this?

Try to input
:server connect
on the sandbox. Your $ will change to neo4j$, and you will be connected to your database.

Hello @juliamizarela and @nzskiwi . Welcome to the community!

Hopefully you were able to connect to the sandbox server ($neo4j prompt appears).

In some cases when there is a dropped connection, you can simply refresh the page and the connection will be re-established.