I am getting a licensing error "unable to register real time event stream. This could be due to licensing or network issues"

This error means you are using more licenses than you have.

If you are licensed for 3 displays this means you can have 3 active sessions running at any time.

You can see how many sessions you have running by clicking display/sessions in the left menu and delete any sessions that are not in use.

For further details on how licensing works please read the following article:

How does the licensing work?