Running into issue with starting service getting error 500

I have no issues with my other courses but for some reason I ma having an issue with this on course.

I am using nbgrader and Jupyterhub for multicourse.

The error I am getting is a JH error. I try to login to the course service and when I do I get the error

500 : Internal Server Error

The error was:

Failed to check authorization: invalid_client

In logs:
[JupyterHub provider:64] Client secret mismatch for service-XXX

You haven’t given us much information, but some general things you can try include restarting JupyterHub, logging out and back in, and clearing your browser cookies or cache.

If you need more help you’ll need to give us more information, such as how you’ve setup JupyterHub, your configuration, and your debug logs.

Jupyterhub setup:

DB using PostgreSQL
JH version 1.4.2
Using systemd spawner
nbgrader 0.6.1

This only happened when I switched instructors so i modified the name and api token.
It was working previously.
‘name’: ‘course’,
‘url’: ‘’,
‘command’: [
‘user’: ‘username’,
‘cwd’: ‘/home/username/course’,
‘api_token’: ‘usertoken’ # include api token from admin user

restarting JH doesnt work recreating the nbgrader config files doesnt work either. Im not sure what section that error would be found in the db.

This can be closed, I figured out the issue. I had a zombie process from the previous service that was causing the issue.