Using a mapped drive letter over a VPN is not a supported environment, and you're seeing why it isn't. You need to use some kind of remote access tool. You could use a Remote Desktop connection over your VPN connect to a Terminal Server or, if you only need one remote connection, you may want to set up a dedicated PC at the main location and use one of the many remote control tools such as GoToMyPC.com, LogMeIN.com, or Team Viewer. The other option would be to use a hosting company for your Sage 50. Then all users would access it remotely and could do so from anywhere they have internet access. I've never used a hosting service so I can't recommend one but a search for "sage 50 hosting providers" should give you several options. You may also want to contact Sage and see if they have a list of approved hosts.

There's one other option that I should mention. Sage 50c allows you to share your data via Sage Cloud. But currently when the data is shared only one user has full access to the data, all other users just have read-only access. Full multi-user access is supposed to become available next summer.

Thanks Steve.....unfortunately it's looking like the issue may not have been related to the VPN as much as a new router we installed. I just posted in another thread about the client computers no longer being able to communicate with the Server or even install using the network drive.

I posted a few suggestions on your other thread. There may be other issues too, but mapping a drive letter over a VPN will most likely be a problem for Sage 50.

Knowledgebase ID:29729 Error: "Sage 50 cannot be started..." when accessing through Virtual Private Network (VPN)

Knowledgebase ID:32024 What are the requirements for using Sage 50 on a Virtual Private Network (VPN)?