From a Windows application, you try to browse to a folder or file on a network mapped drive and the drive can't be selected. Only the local drives are available.
When User Account Control (UAC) is enabled, if you run a problem a program as Administrator (elevated), you can't see network drives unless a registry setting is changed to allow it.
This is because the mapped drives were created under a login different from the administrator login.
Notwithstanding how ridiculous it is that running as Administrator gives you fewer permissions than other users and prevents you from seeing the mapped drives, the solution is a simple change to the registry. Alternatively, you can login as Administrator and remap the drives.
The following information presumes you know and are allowed to make Windows registry changes.
The EnableLinkedConnections value needs to be set to 1 under HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System
You can download and run this REG file to implement it. It's contents are:
Windows Registry Editor Version 5.00 [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System] "EnableLinkedConnections"=dword:00000001
For your convenience, you can download it here: policies.reg
For more information, read this Microsoft KnowledgeBase Article 3035277: