For our edited fields, I pressed tab to auto-fill the field name. The result would end the field name with _c. I tried to edit the field names (EX: Meeting_ID) but it still shows _c at the end.
Here is the list of errors found on the grader app.
How do I solve this issue?
The field LABEL is what users set and refer to but, internally, Salesforce uses the field NAME which is supposed to have the "__c" at the end. Those are what we check in the grader app. That's not causing your errors. It looks like your field labels weren't spelled exactly right so the field names that they generated weren't exactly right either. For example, on the 2nd row of errors, it says it found a field with name "Meeting__c" in the Meeting Attendance object. That means the field label was set to "Meeting" but it should have been "Meeting ID". I think the rest are similar errors and they're correctable but you have to change the field NAMES too because that is what's checked by the grader app (by necessity).