Starting November 7, 2018, the Dropbox client will only support the Ext4 file system on Linux

Starting from November 7, 2018, the Dropbox client will only support the Ext4 file system on Linux. News from Dropbox ForumIt is mentioned that the only supported file systems are Linux Ext4, Windows NTFS and Mac HFS+ or APFS.
Dropbox users have started receiving notifications about this message, which mentions: “Move Dropbox location. Dropbox will stop syncing in November” without any other details.

If you receive this notification and you are currently using a supported file system, you may have a computer linked to Dropbox running on an unsupported file system. If you no longer use the computer, you can unlink it from your Dropbox account from: HereUpdate: Dropbox support members also have confirmed To Dropbox users who do not support LUKS/ecryptfs on Ext4 file system.
For why this is happening, the forum post mentions the following:

Because Dropbox relies on extended attributes (X-attrs) to identify files in the Dropbox folder and keep them in sync, a supported file system is required. We will continue to support only the most common file systems that support X-attrs, so we can ensure stability and a consistent experience.

Interestingly, in addition to ext4, there are many Linux file systems that support xattr (extended attributes) when enabled in the kernel configuration, including ext2, ext3, Btrfs, XFS, JFS and other.
If you are looking for a dropbox alternative with full Linux support, you can run your own Nextcloud instance or use Nextcloud provider. Spider oak It is also a good choice (it is not open source, but it is created using encrypted cloud storage and client encryption keys).
You can also use the following alternative methods:

  • Use the workaround to make Dropbox run on non-Ext4 file systems (Btrfs, Ext3, XFS, ZFS, etc.) and encrypted partitions on Linux
  • Use Maestral, a new open source Dropbox client for Linux and macOS that supports synchronization when using these “ucommon” file systems (such as Ext3, Btrfs, XFS, ZFS, and encrypted partitions)

Dropbox logo image credits: Wikipedia; News from Reddit.