Are you only allowed to create four dashboards?
You are allowed to create as many dashboards as you need, but you can open only 4 dashboards in one tab of your browser at a time. This is a technical limitation, which was established to maintain stability of the app.
Currently you can use the ability to open any number of browser tabs with any set of dashboards. You can also open one dashboard in different browser tabs simultaneously. All changes occur in real time.