Local Files Cannot Be Connected via Tableau Prep Conductor with Error: "The output file path is not valid or you don't have permissions to write to the file"

Issue

Connecting to local files in Tableau Prep Conductor results in errors such as the below:

"The output file path is not valid or you don't have permissions to write to the file. Check permissions, verify this file path is in the safelist, or use a valid output file path."

And/or

"Connectivity error. Unable to connect to the output location for output step [name]. Try again, or download the flow and edit the output location for the output step, then run the flow again."

Environment

Tableau Server 2019.1
Tableau Online
Tableau Prep Conductor

Resolution

Tableau Server: You need to safe list files for use by Tableau Conductor. For more information, see Enable and Configure Tableau Prep Conductor on Tableau Server, STEP 4: Safe list Input and Output locations.
Tableau Online: You need to change the output connection in the flow from "save data source to network drive" to "publish data source", then republish the flow to Tableau Online.

Cause

Tableau Server: File locations need to be "safe listed" in order to be available for Prep Conductor.
Tableau Online: Tableau Online does not have the ability to connect to a network drive because it is hosted externally (internet facing).