I am using DropBox quite a bit to move files around between various machines (nothing confidential, just stuff that I need to move around and that is a tad on the large side). Today, I hit a very issue where I saved screenshots from a Ubuntu machine and waited for them to show up on a Windows machine. And they never did. Confused, I went to the web interface, and the files were indeed in place there. I could download it from the web interface without an issue. Weird. Other files did sync in the meantime, so just what was going on?
After some digging around Dropbox help, I found the article “My files aren’t syncing or are slow to sync“.
I first tried fiddling with speed throttling and bandwidth limitations, but that had no effect.
But some distance down the page, there is a heading (that seems to be impossible to link to directly) “I’m connected to the Internet and signed in to the same account on my devices, but files aren’t syncing—are there issues with the files?”. This turned out to be the key. I opened the link https://www.dropbox.com/bad_files_check, and it told me that a few files wouldn’t sync due to file name issues.
The files all had names like “Screenshot from 2015-08-28 09:36:42.png“… and colon is not an acceptable character in an NTFS file name. See the MSDN article here. You are not allowed to use:
< (less than)
> (greater than)
” (double quote)
/ (forward slash)
| (vertical bar or pipe)
? (question mark)
And Dropbox simply does not drop those files to your local disk without any locally visible warning or error. I guess it would be nice if it could at least warn about it… instead of silently just not synchronizing the files. Silent failure is rarely a good user interface.