Hi David
Thanks for your response. I played around with the config and the way I got it working is by changing the permissions of the error dashboard to restricted group.
So in dashboards.csv, if I change the below entry from
dashboard,usergroups
10ec73be-e822-7e49-1159-037697f15bf1,admin
to
dashboard,usergroups
10ec73be-e822-7e49-1159-037697f15bf1,restricted
Not sure if this is the right way, but thats the only way i have found it to be working.