Fix common migration validation errors

Quick answer

The validation report lists row numbers and fields to correct — fix the file and re-upload.

Frequent errors

• Invalid date format — use ISO dates (YYYY-MM-DD).
• Unknown store name — create the store first or fix the reference column.
• Negative balance — balances must be zero or positive.
• Duplicate card code — each code may appear only once per migration file.

Steps

1. Download the error report after validation.
2. Correct the source spreadsheet.
3. Re-upload until validation passes with zero blocking errors.
4. Keep a backup of the final file for audit purposes.