I am importing vendor bills with a CSV import. But I am getting "Mandatory Field Missing for field "External ID" even though it is mapped. What can cause this?

When we see this it is usually due to data having been on a row that is maybe still there or was just cleared instead of removing the line. It can usually be resolved by editing your import file, grab your first blank row then drag down to select another large chunk then do the right click and delete rows, save and try again.

Amazing, that did the trick! Thank you