what do you mean "try to schedule a workflow from a remote drive"? A drive is a storage unit and you don't schedule from a storage unit. Scheduling is an action taken via the Scheduler software which runs on your machine where you have it installed and running per your most recent comment "I do have the Scheduler/API add-on license.
The scheduler runs on your machine and the workflow and files may exist on your hard drive or a connected storage system or drive. By connected storage system or drive I mean a drive on someone else's machine that is open and shared to you or more likely a network attached storage system of your company's.
If the workflow is on a drive/storage remote to your machine then you must have access to that drive for the scheduler to find it and run it.
The only other scenario that comes to mind is that you have the scheduler license on one machine, say a desktop at work, then remote in to that desktop to schedule a flow that is on a drive/location which is not accessible to that remote machine running the Scheduler system....such as the laptop/machine you are "remoting" in from. A machine you are using to remote access another is not by default accessible by the other machine you are accessing remotely. This puts you in that same situation I explained previously about local drives not being shared typically. A machine you use to remote to another is not visible to that machine being remotely accessed by virtue of the remote connection. hope that makes sense.
