One day I discovered that certain files and folders in my Dropbox folder had a red circle with an ‘x’ in it on their icons. According to Dropbox.com, this means they can’t be synchronized by Dropbox. All other files in the Dropbox folder were synced just fine.
Dropbox suggests that you:
- Check if you filled your Dropbox quota
- Restart your computer
- Disconnect and reconnect your desktop Dropbox application
- Check that there is no anti-virus software getting in the way
- Check that your computers system time is off
- Check that your computer can’t get a secure connection
- Check whether your are using a proxy that is not configured for Dropbox
- Check whether the file permissions are set to a different user. This can happen if you changed the system account name.
If all this is not the problem, they mention that you can use OS X Terminal to change the HFS+ system file flags, with the command chflags nouchg filename.
But even that didn’t make the red dot go away on my files. Then I found out that all files were in a folder with a backslash in the name. To understand why this struck me, you must know a little bit about OS X’s roots. Traditionally, in *NIX systems, punctuation like slashes and colons were often reserved for specific tasks and therefore called ‘special characters’. That’s why even today in Mac OS X you can’t use – for example – a forward slash in a file name or folder name. You can use a backward slash in the Finder though.
Backslash is the cause that certain files won’t sync in Dropbox
Still, a backslash breaks Dropbox syncing. Simply remove the backslash from your folder and file names to get Dropbox to synchronize them again.