Missing column in a CSV import: check for a BOM

Symptom. The import reports a missing column. The leading column name looks right on screen, or shows odd characters before it.

Fix steps. Work on a copy. Keep the original untouched. In some editors, the save dialog offers an encoding choice. Pick the option without a byte order mark. In some editors, a status bar shows the current encoding. Save the copy under a new name. These steps are untested.

Retry. Run the corrected copy through the same check again. Compare it with the earlier result. If the message remains, look at other header differences such as spelling or spaces. Change things separately.

Some apps show accented letters more reliably when the file starts with a byte order mark (BOM), while some imports then miss the leading column name. If accented letters look wrong after saving without one, see "Why accented letters look broken in your CSV" and test each copy in the app that will import it.