You may run into an issue either downloading or uploading files to and from your WebTier environment.
Sometimes the culprit may be the GPOs you have set.
Keep in mind, you will need to make sure that both your Local and Global GPOs are set in the following location:
Computer Configuration\Policies\Administrative Templates\Windows Components\Remote Desktop Services\Remote Desktop Session Host\Device and Resource Redirection\ "Do not allow drive redirection"
Set to either "Disabled" or "Not Configured"