A workflow pauses when you paused it, when it hit an error it couldn't recover from, when a dependency (integration or signal source) disconnected, or when a safety guard tripped. The workflow's run log shows the pause reason.
Check the run log
Workflows → your workflow → Runs. The most recent run shows why it stopped — a manual pause, a step error, a disconnected dependency, or a guard that halted it to prevent a bad bulk action.
Common causes
Someone paused it; a step failed (a mapping error, a downstream API rejecting the call); an integration the workflow depends on disconnected (see Why did the integration disconnect?); or a safety guard stopped it because it was about to act on far more records than expected.
Fixes
Resolve the underlying issue — fix the failing step, reconnect the dependency, or confirm the large batch is intended — then resume. Resuming without fixing the cause just pauses again on the next run.
Safety guards
Workflows that suddenly target a huge record set are held on purpose so a bad trigger doesn't email your whole database. If the volume is legitimate, acknowledge and resume; if not, you just caught a mistake before it shipped.