Dropbox: Certain Files Won’t Synchronize

Here’s a very interesting problem I encountered just last week. I was speaking to a colleague over the phone, and she told me that she had placed a particular document in a folder that we both shared on Dropbox. I looked into that folder, but was unable to locate the file that she spoke of. At that point, I realized that the Windows client really had no way of reporting whether it synchronized properly, or not. No matter what I did, the Dropbox client was convinced that everything was synchronized.

Since I wasn’t getting much information from the desktop client, I decided to log into the website. Surprisingly, the file was visible from the web interface – but it wasn’t appearing on my computer. Here’s what it looked like, roughly:

A word document titled "5E:Dolphins.docx" can be seen in the Dropbox web interface.

Notice anything… uncommon? It’s not often that I see colons in filenames, and so the sighting stood out to me. I then recalled that my colleague used a Mac, rather than a PC. I had a feeling that the colon character was invalid in Windows, and I decided to test my theory.


Sure enough, Windows blocked me from creating a text file with a colon in the filename, and it showed me the following message:

A filename cannot contain any of the following characters:
\ / : * ? ” < > |

To fix the problem, I simply asked my colleague to remove the colon from the filename. As soon as she did, Dropbox downloaded the file to my computer, and all was well. It turns out that this problem is well documented on the Dropbox help site, and that they even created a tool that helps identify problem files.

In the end, I feel it is Dropbox’s responsibility to improve the way the client reacts to such problems. Without my background in Computer Science, I probably wouldn’t have discovered the source of the problem within a reasonable time. Unfortunately, it seems that the issue isn’t getting many votes within Dropbox’s suggestion forum. Let’s hope they decide to implement it anyway, to improve the quality of their service.

See Also

Dropbox Help: Why aren’t certain files on one computer syncing to another?


  • dc

    Yeppp… Dropbox isn’t as perfect as they’d like you to think.

    I’ve been having trouble this week getting it to upload a changed file from my phone to the server. It had the “waiting to upload” status message on it for about 24 hours, even though I was on my home wifi…! And repeatedly sync-ing in the app did nothing.

    IMHO they give too much emphasis on uploading from the PC client. Their help page doesn’t even acknowledge the possibility that you might use their own DB Text Editor to change a file on your phone. Strange strategy for a tech company to ignore mobile.

  • Reagan Snow

    Thank you so much for posting this.

    My wife has a Mac and I have a PC. She spent 15 minutes trying to figure out why a particular file wasn’t showing up on my laptop before finally stumbling across this article. She took out the / in the title and made it a – instead, and the file showed up instantly on my PC.

    It never gave an error message – it just didn’t show up. We never would have known what was happening without your article. Thank you!!