The same bounce back just happened to me with that same error message. In addition they reduced the $9.75 they had been paying for these same drive-up shops in December, down to $9.00. The observation stuff they asked for was extra narrative boxes, in addition to other added question boxes.
Bottom line, they have reduced the pay on these shops and significantly added extra questions and narratives to the report. Adding insult to injury, they ask for the additions after the reports were submitted. In my case 5 reports.
I completed over 50 successful shops for them last year and I will not accept any further assignments under these conditions. It is clear to me they don't care about walking all over their shoppers.
This is my first post on this board, but I felt I needed to vent and warn other shoppers about this company.