Thanks. I actually have the file on my Mac in a DropBox folder. It is a local folder and not hosted. My Windows machine has access to the Dropbox folder as well. It isn't a real-time type of share. But either way, I gather this is no good.
Can the Windows machine still use the DropBox if it opens through Remote Access (as described in the link)?
The problem with regular network file sharing is that I don't use it. Connections between the Mac/Windows machine are very unstable. That connection will drop for no reason. The only way to re-establish it back is to reboot one of the machine. Hence the reason I use the Dropbox. Plus it is a remote backup.
When you share files with Dropbox, each person has their own local copy. I keep a few FileMaker files in my Dropbox, and AFAIK this is safe enough, as long as each user (just me in my case) is sure to wait for full upload/download before attempting to open the file. I wouldn't do this for any mission-critical databases.
But for multiple users, the problem is you'll have multiple copies of the database, and they'll get out of sync unless you never ever have the file open at the same time.
Now, you could open the file on your Mac, and the Windows machine could then use Open Remote in FileMaker to access it, but that won't solve your unstable connection problem. (Even though keep in mind you SHOULD NOT USE REGULAR NETWORK FILE SHARING, only FILEMAKER host/client sharing.)
Perhaps you should look into a FileMaker hosting service, there are a handful of such companies.
It's only me. Two computers on a home network. Don't need to spend extra money on hosting services. Not that elaborate.
If I open a data file on one machine, I'll be sure it is closed on the other and that everything is sync'ed in Dropbox. Seems the safest way.