500 error: "Company admin not found."

Making a request to https://api.7shifts.com/v2/companies I'm getting a 500 error:

{"error":"unknown_error","error_description":"Company admin not found.","title":"Company admin not found.","type":"https://httpstatus.es/500","status":500,"detail":""}

What does this error mean and how should I handle it?

I can provide client ID and company GUID privately if needed.