I created a new Dashboard and called it 'Dashboards'.
Now when I click Menu Dashboards, instead of displaying all dashboards, it displays this newly created dashboard. Now I cannot access all dashboards at all.
Is this allowed in Splunk?
Splunk should throw an error that Dashboard can't be named as 'Dashboards'
either in the Splunk UI goto Settings » Views » User interface and delete your Dashboards dashboard (Not the one from the search App!) or delete it on the file system if you have access. It can be found here:
On a side note, the problem is not the title of the dashboard, it's the name of the file on disk (Splunk sets the file name according to the title though). What you can do to have a dashboard named "Dashboards" is, after you've cleared your splunk up, create a dashboard with any other name that is not "Dashboards", edit the Simple XML of that dashboard and change the content of the <label> tag to "Dashboards". Your dashboard will now have the title "Dashboards" (both in the list of Dashboards and on the dashboard itself), and the original "Dashboards" menu entry will still take you to the list of dashboards.