How to upload CSV import file which has failed with 'Invalid file' error in Assets

Summary

Learn why a CSV file upload fails with "Invalid File" error in Assets import.

Diagnosis

While a CSV file is uploaded in the CSV import, the upload fails, and it throws "ERROR Invalid File."

Cause

The file is not correctly formatted

Asset import can't read the file correctly because the file might be corrupted or improperly configured.

Solution

Check the CSV file for issues

Open the CSV file in a plain text editor (not Excel or Google Sheets, which can silently reformat data) and confirm there are no extra trailing commas (duplicate column names), no stray blank lines (empty columns) at the end of the file, and that the file is saved with UTF-8 encoding — these are common causes of a generic 'Invalid file' response across CSV import tools.

If the full file still fails after checking formatting, isolate the problem by re-uploading a minimal test file containing only the header row and 2–3 sample rows — if that succeeds, the issue is with specific data further down the original file rather than the file structure itself.