Dropbox – Cannot Sync File Due to Space Constraints

The current version of Dropbox suports selective sync, it is explained in the dropbox help. Here's how to do it, check the help link for more advanced cases.

1. Click on the Dropbox icon from the system tray
2. Select Preferences
3. Click the Advanced tab
4. Click the Selective Sync button

A window will appear with a list of all the top level folders in your Dropbox folder. The folders with a check next to them will be synced to your computer. Uncheck any folders that you don't need to sync to your computer's hard drive. When you're done, select OK. Any folders you deselected will be removed from your hard drive, but will still be available through the website and on any computers linked to your Dropbox account.

Use the Advanced View button to drill down into the folders in your Dropbox. Click on the arrow next to the folders in your Dropbox to drill down and check or uncheck folders deep within your Dropbox hierarchy.

This problem seems to be linked to "the Turkish issue" (involving both dotted and non-dotted versions of i). There is some kind of duplicate checking mechanism in Dropbox to side step problems with case insensitive file systems. In site of their claim to full UTF-8 support there is at least one bug affecting syncing of folders that contain characters that don't convert from upper to lower case and back round trip using generic algorithms.

Removing all content with the non English ı and İ characters solves this sync issue.

Once everything is in sync again across platforms, adding the content back in as find as long as there is there is not a file that would be ambiguous giving a non-case sensitive file system and a case conversion involving those letters.