Customize How Records Get Approved with Approvals

After reading all the posts and various error messages I went and made some corrections to my approval process.  
But I still get the following error:

Challenge Not yet complete... here's what's wrong: 
There was an unexpected error in your org which is preventing this assessment check from completing: System.DmlException: Process failed. First exception on row 0; first error: REQUIRED_FIELD_MISSING, missing required field: [nextApproverIds]: [nextApproverIds]

I am not sure what it means by missing required field: [nextApproverIds] does anyone have an idea on how to fix this or is this another known issue with this module?

Thanks