If you are getting an error message 'Workflow exceeded maximum runtime of XX seconds and was canceled', you may need to change your system settings to allow a workflow to run longer. From Alteryx Designer, go to Options --> Advanced Options --> System Settings. (Note: if you are running Alteryx Server and don't see the System Settings, you will need to contact your server administor and have them help you make changes to the System Settings). Click 'Next' until you get to the Worker Configuration. If the 'Cancel jobs running longer than (seconds)' option is checked, the seconds can be increased here.
This message will be generated for scheduled workflows and workflows being run from a gallery if the option has been checked and the workflow runs longer than the setting allows.