Overview
Every scheduled pipeline runs under a specific user (the "actor"). If that person leaves your VCS organization or loses access to a required context, the schedule silently stops firing. This is the most common reason a previously working schedule stops without any config changes.
The trigger actor left the organization
How to check:
Go to Project Settings and find your schedule trigger:
GitHub OAuth / Bitbucket Cloud: Select Triggers in the sidebar.
GitHub App: Select Project Setup in the sidebar, then locate your pipeline's schedule.
Check the Attribution field for the schedule. It shows which user the pipeline runs as.
Confirm that user is still a member of your VCS organization.
How to fix:
Click Edit on the trigger.
Change the Attribution to an active user or to Scheduled Actor (Scheduling System).
Save the trigger.
Tip: Consider using a machine/service user for scheduled triggers so they are not tied to any individual team member.
The trigger actor lost context permissions
Even if the actor is still in the organization, the schedule will fail if their access to a required context has been revoked — for example, if they were removed from a security group.
How to check:
Go to Organization Settings → Contexts.
Select each context used by the scheduled workflow.
Verify the trigger actor is in the allowed security groups.
How to fix: Either add the actor back to the security group, or change the trigger's Attribution to a user who has the required context access.
Note: If using the Scheduled Actor (Scheduling System), be aware that it may not work with context security group restrictions. Use a real user account in that case.