Scheduled Conga Batch Failed to Run
If your scheduled Conga Batch fails to run, the first thing to check is whether the Master Switch on the Conga Batch Setup Tab is enabled (which is required for Conga Batch schedules to run). If it is not enabled, it is possible the Master Switch was disabled due to a Salesforce limitation in which a user can only have four OAuth tokens per application.
Why Does This Happen?
This can also happen if you click Allow too many times when generating a debug URL since it also creates an OAuth token.
What to Do
One thing you can do to help ensure the Master Switch is not disabled from too many OAuth tokens being created is to change the default Launch button on the Conga Batch record to use the non-OAuth Launch button that came with the package (the one that says "APXT_BPM__Launch_Dev" when hovering over it. See screenshot below).
To change the button: