Something disappeared from my items after an upload

Content Uploader writes exactly what your file says to every field you mapped. When a value is gone from an item after an upload, the file said it should be, and that can happen in ways that are easy to overlook. Nothing is lost for good: the file, the site's own history and a second upload can bring it back.

Symptoms#

• An excerpt, a list of tags, a category, a featured image, a custom field or the content is empty on items that had it.
• A post's web address (its slug) changed.
• Something you edited by hand on the site was put back to what the spreadsheet says.

Likely causes#

Confirmed (reproduced in our tests, on a WordPress site):

1. An empty cell in a mapped column. Content, excerpt, categories, tags, the featured image and custom fields are removed when their cell is empty; an empty slug makes WordPress build a new one from the title; an empty Status, Publish date or Author removes nothing, because it has no value to send (empty cells).
2. Replace means replace. When a row changes, every mapped field is sent, so a person's edit to any of them on the site is overwritten by the file's value. A status changed by hand is announced in the review (Changed on the destination since it was published. Publishing restores this file's values.); other edits are not.
3. A column that is mapped but was blank in this week's export, for example because the source system had no data for a day.

From the program's own rules:

4. Remove from every item was chosen for the field: it empties it on every item the file publishes.
5. Replace with configured terms for categories or tags: the file's terms become the item's only terms.

Step-by-step solution#

1. Do not upload anything else yet. A second upload with the same blanks removes more.
2. Find the cause in the file: open the spreadsheet and look at the cells of an item that lost something. Is the cell empty? Was the field's mode Remove from every item or Source column?
3. Put the values back in the file and upload it again. The review lists the items as updated, with the old value shown as the new one; publishing restores them. We tested this end to end: after a file whose empty cells had cleared an excerpt, tags, a category, a featured image, a custom field and a slug, uploading the original file restored every one.
4. Or use your site's own history. WordPress keeps post revisions (Edit → Revisions) and Joomla keeps Versions for articles, where they are switched on (can I undo a publish?).
5. To stop it happening again, choose Keep existing on updates for fields that the site should own (a status, an excerpt an editor polishes, tags added on the site), or fill the cells, or do not map the column.

How to verify#

• The review of the corrected file lists the items as updated and shows the values coming back.
• After publishing, open an item on your site and check the field.
• Uploading the same file once more finds everything unchanged.

If it persists#

• If the file has the values and the site still lacks them, open the item's review entry and read what it says it will send; contact support with the record ID and a screenshot.
• If a person's edits keep being overwritten, that is the mapping working as designed: set those fields to Keep existing on updates.