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title: Alert rules on failed checks: MTR unreachable and DNS errors now fire
description: The MTR "Destination Unreachable" and DNS "DNS Errors" presets could never fire, because a failed check skipped every rule wholesale, including the ones meant…
canonical: https://watchfor.io/changelog/2026-09-03-alert-rules-on-failed-checks
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[All updates](/changelog/page/5#2026-09-03-alert-rules-on-failed-checks) 🐛 Fixed Sep 3, 2026 · v 6.4.3

# Alert rules on failed checks: MTR unreachable and DNS errors now fire

The MTR "Destination Unreachable" and DNS "DNS Errors" presets could never fire, because a failed check skipped every rule wholesale, including the ones meant to catch exactly that failure. That was our bug. Rules are now evaluated whenever their metric is present in a failed result, so those two presets fire for the first time and FTP/SFTP connection and listing rules keep working when only the write test fails. Response-time rules still never fire on a failed check.

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Canonical page: https://watchfor.io/changelog/2026-09-03-alert-rules-on-failed-checks · Site guide: https://watchfor.io/llms.txt