>>>>Have a VFP Application which does a File Copy from a mapped Drive. Works fine in XP, Win7 & Win8.
>>>>
>>>>In Windows 10 am getting a File Not Found Error even though the Mapped Drive and File are visible in Windows Explorer.
>>>>
>>>>Anyone else had this issue?
>>>
>>>Have you checked to make sure you don't have a drive letter conflict *before* establishing the drive mapping?
>>
>>No mapping conflict.
>
>What I'm hearing so far is:
>
>- No problem with machines running Windows 7 or 8.1
>- Problem with a different machine running Windows 10
>- Problem running the app in Win7 compatibility mode on the Win10 machine
>
>So the problem is not with Windows 10 per se, it's something different in the configuration of that particular machine or its environment.
>
>Everyone is going around in circles here. If this is a significant problem which you need to resolve I suggest you give us some background:
>
>- Is it a physical computer or a virtual machine?
>- Version of Windows 10 (Home or Pro, 32- or 64-bit)
>- Is the machine domain-joined?
>- What type of account is being used to run your app: local/user, local/administrator or domain? I've seen cases where tech support has forgotten to make a domain account a member of a local user or admin group, so the domain account has no privileges on a local machine and apps won't run
>- How are the mapped drives being mapped? In a logon script or group policy? Or interactively by the user? With or without the remember/persistent switch?
>- Does the app do any drive mapping itself? Remember you can't change a mapping from \\Server1\Share1 to \\Server2\Share2 directly; you have to delete the mapping first, then re-map to the new server\share
>- Are you running the app normally (i.e. interactively) or are you running it as a scheduled task via Task Scheduler?
>- Is this a conventional desktop app or are you running it through Remote Desktop or RemoteApp?
>- Are there any unusual processes that hook the file system and may interfere with access e.g. overly aggressive antivirus, so-called "real-time" backup utilities etc.
>- Is it a tightly controlled or locked-down environment that may restrict folder access by user account?
>
>It's worth pointing out that avoiding these kinds of problems is one reason to use UNC naming conventions rather than mapped drives.

Step 1. Can you do a CD to the drive/folder? If not, then all bets are off until the permissions problem is fixed. This is where he's at - so until that is resolved then nothing else matters.