GOG Galaxy *really* does not like network drives. It has not been written to correctly determine the "free space" remaining on such drives. As such, it fails with "out of disk space" errors, if you have configured it to use a network drive.

The problem exists whether you use the network share directly, or "map" it to a local drive. The GOG Downloader does not appear to have this same problem.

To remedy,
Go to the GOG Galaxy configuration and make certain these items are NOT configured to use a network drive:
* Install games to:
* Download games to:
* Download extras to:

This is sad, as many users now store their download games to a NAS, and install them locally. Such is the life of Beta products.

Hope this helps,
chinajade