I have my sheet set up and saved. Then, I created a report based on columns in the sheet. I added the following columns, saved the report. Data already in the sheet was showing in these columns.
Now three times, I've opened the report, and these columns keep showing up as Columns Not Found. I unchecked the columns and added them again to the report. The names have NOT changed or deleted or renamed.
If I look at the columns in the report (see below), the data is still showing up even though I have those error icons in the dropdown..
So I don't understand why the dropdown is showing these columns as having errors.