Mostly AI synthetic generation error job failed validation sensitive column detected

TL;DR

Fix this in Mostly AI by acting on the exact message first: classify the flagged column correctly in the generator config, remove direct identifiers such as names and government id numbers from training entirely, and keep only the columns the synthetic output actually needs. Do not rerun the whole job unchanged, because the same inputs produce the same failure. Prove the fix on one table, batch or record set first, then rerun the full scope and reconcile the counts.

job failed validation - sensitive column detected

Use this when

• The operation in Mostly AI fails with this exact message or symptom: job failed validation - sensitive column detected.
• The same failure repeats on retry with unchanged inputs.
• Generation, validation or export is blocked until this item completes.

Not for this skill when

• The message is an outage notice from the platform. Resolve that first, then return here if this error remains.
• The operation completes and you only disagree with its output quality. That is a quality review, not this failure.

Steps

1. Reproduce the failure with the smallest scope that still shows it in Mostly AI, and copy the full message plus the table, column or job involved into the run notes. Verify: the error is reproduced on demand with a named scope, not only seen in a log.
2. Apply the specific fix for this error: classify the flagged column correctly in the generator config, remove direct identifiers such as names and government id numbers from training entirely, and keep only the columns the synthetic output actually needs. Verify: the smallest failing scope now completes, or the named column, table or job behaves as the fix predicts.
3. Check the neighbouring tables, columns or jobs that share the same config, schema or credential, because this class of failure rarely affects only one item. Verify: the neighbouring items are listed and each is marked affected or clear.
4. Rerun the original operation in Mostly AI on the previously failing scope, watching for the same message rather than assuming success from a quiet log. Verify: the operation completes and the original message does not appear.
5. Compare the result counts, distributions or status against the source in Mostly AI so a silent partial success is caught before sign off. Verify: counts match the source or every difference is named and explained.
6. Record the fix, the triggering input and the verification result on the item so the next occurrence is recognised immediately. Verify: the record names the error, the fix applied and the evidence of success.

Why it happens

Mostly AI blocks training when a column looks like a direct sensitive identifier that has not been classified or excluded, because synthesising it would reproduce identifying values.

Variant phrasings

job failed validation - sensitive column detected

The verbatim form searchers paste from the terminal or console. Treat it identically: same fix, same single scope proof, then the full rerun.

How to fix - Mostly AI synthetic generation error job failed validation sensitive column detected

The how-to phrasing for the same failure in Mostly AI. The steps above apply unchanged; start at the reproduction step rather than skipping to the rerun.

Mostly AI troubleshooting for this failure

The symptom-first phrasing used when the console hides the full message. Surface the full message first, confirm it matches the code block above, then follow the steps.

Compatibility: Mostly AI at current versions, plus the platform API or console the query names; no extra tooling beyond the source system access needed to verify counts.

Provenance

Resolved from the public thread: https://vectle.com/posts/pst_FLZOf7CgIbTW5ja6WtR32w