Error "invalid client"

I am successfully using a Python script (that uses the GitHub - Patreon/patreon-python: Interact with the Patreon API via OAuth library) to pull my campaign’s pledges and use that to synchronize membership levels on my web site. However, it has some problems where it’s not quite pulling all pledges (it’s missing a few). In order to debug this further, I am trying to create a second “test” client with its own client ID and secret so that I can debug on my local system (any use of the primary client ID and secret results in invalidating the system that uses it, so I don’t want to use it locally for debugging).

The problem I am having is that I simply cannot get a valid access token by using my test client. No matter what I try, I get the response {'error': 'invalid_client'}. Is there a reason why this might be occurring? Is it not possible to create a second test client for debugging?

After getting a second set of eyes, it appears that the client ID I was using was copied and pasted incorrectly. It was close, but because of some special characters, it was cutting off towards the end.