If you have Windows systems on your local network, and have them configured to share files with Windows file sharing, then they should appear in your Mac’s Finder sidebar where you can connect and copy files. However, there may be times when in doing so, you will be able to browse files but not be able to open or edit them, even though there is no indication of a permissions restriction or other barrier.

This problem is likely from some nuance compatibility bug in Apple’s Windows file sharing technologies. In prior versions of OS X, Apple used the open source Samba suite for implementing the “SMB” networking protocol, but open source licensing prevented Apple from customizing the software to its liking, so it developed an in-house SMB alternative. This implementation has worked quite well for the most part, but still has some odd bugs that you might run into.

Unfortunately there is no direct fix that will overcome this issue, but you can work around it by forcing OS X to use an older SMB networking protocol, included for compatibility. By default, OS X targets Windows systems using the “SMB://“ prefix, which specifies the next-generation SMB2 protocol, but if you target a system with the “CIFS://“ prefix, then you will force OS X to use SMB1. While this may affect network performance a little, and change how symbolic links and some other details are handled, it should allow you to connect to your Windows share and edit your documents:

1. Get your Windows system’s IP address, NetBIOS address, or other full domain name address.
2. In the OS X Finder, press Command-K.
3. Type “cifs://ADDRESS” in the Server box, where ADDRESS is your system’s IP or other address.
4. Press Enter to connect, and authenticate if prompted.

If you do not know your Windows system’s IP address, then you can look it up using the OS X Terminal using the following approach:

1. Open the Terminal utility (in the Applications > Utilities folder).
2. Type “smbutil lookup” followed by a single space.
3. Type the name of the Windows computer as it appears in your Finder sidebar, or otherwise in the Finder (this is the NetBIOS name).
4. Press Enter, and you should see the system’s detected IP address listed.

Note that OS X should resolve the NetBIOS address if supplied in the Server address box; however, if you are having trouble connecting then using the IP address should be a more direct route to the remote system.