Description of problem:

When you try to access the Spawner page using a user without enough permissions (outside the allowedGroups/adminGroups) the error page reports:

Page Not found 
Uh oh, this page appears to be missing. Move along. Nothing to see here..

I think it should state something like "Ensure to have enough permission to access this page" or similar to make it clear that is a permission issue.

Prerequisites (if any, like setup, operators/versions):

Steps to Reproduce

1. Log in RHODS Dashboard with a user outside allowedGroups and adminGroups
2. Try to launch Jupyter from "Enabled" page

Actual results:

"Page Not found" error

Expected results:

descriptive error

Reproducibility (Always/Intermittent/Only Once):

always

Build Details:

RHODS v1.16.0-dashboard-kfnbc provided

Workaround:

Additional info: