Suddenly, Ubuntu Dropbox wants authentication and won't start

[eater]

I've been running Dropbox on my Ubuntu 18.04 desktop just fine for months. Today, I noticed the application had stopped, so I tried to start it again and it said "Authentication is needed to run '/bin/sh' as the super user." Whether or not I authenticate, it then goes into "Starting..." status forever.

I've tried removing the current installation and reinstalling, but that doesn't make a difference.

Here's the terminal output:

dropbox: locating interpreter
dropbox: logging to /tmp/dropbox-antifreeze-PZrvIR
dropbox: initializing
dropbox: initializing python 3.5.4
dropbox: setting program path '/home/eater/.dropbox-dist/dropbox-lnx.x86_64-56.4.94/dropbox'
dropbox: setting home path '/home/eater/.dropbox-dist/dropbox-lnx.x86_64-56.4.94'
dropbox: setting python path '/home/eater/.dropbox-dist/dropbox-lnx.x86_64-56.4.94:/home/eater/.dropbox-dist/dropbox-lnx.x86_64-56.4.94/python-packages-35.zip'
dropbox: python initialized
dropbox: running dropbox
dropbox: setting args
dropbox: applying overrides
dropbox: running main script
dropbox: load fq extension '/home/eater/.dropbox-dist/dropbox-lnx.x86_64-56.4.94/cryptography.hazmat.bindings._constant_time.cpython-35m-x86_64-linux-gnu.so'
dropbox: load fq extension '/home/eater/.dropbox-dist/dropbox-lnx.x86_64-56.4.94/cryptography.hazmat.bindings._openssl.cpython-35m-x86_64-linux-gnu.so'
dropbox: load fq extension '/home/eater/.dropbox-dist/dropbox-lnx.x86_64-56.4.94/cryptography.hazmat.bindings._padding.cpython-35m-x86_64-linux-gnu.so'
dropbox: load fq extension '/home/eater/.dropbox-dist/dropbox-lnx.x86_64-56.4.94/psutil._psutil_linux.cpython-35m-x86_64-linux-gnu.so'
dropbox: load fq extension '/home/eater/.dropbox-dist/dropbox-lnx.x86_64-56.4.94/psutil._psutil_posix.cpython-35m-x86_64-linux-gnu.so'
dropbox: load fq extension '/home/eater/.dropbox-dist/dropbox-lnx.x86_64-56.4.94/linuxffi.pthread._linuxffi_pthread.cpython-35m-x86_64-linux-gnu.so'
dropbox: load fq extension '/home/eater/.dropbox-dist/dropbox-lnx.x86_64-56.4.94/linuxffi.fcntl._linuxffi_fcntl.cpython-35m-x86_64-linux-gnu.so'
dropbox: load fq extension '/home/eater/.dropbox-dist/dropbox-lnx.x86_64-56.4.94/linuxffi.sys.compiled._linuxffi_sys.cpython-35m-x86_64-linux-gnu.so'
dropbox: load fq extension '/home/eater/.dropbox-dist/dropbox-lnx.x86_64-56.4.94/cpuid.compiled._cpuid.cpython-35m-x86_64-linux-gnu.so'
dropbox: load fq extension '/home/eater/.dropbox-dist/dropbox-lnx.x86_64-56.4.94/linuxffi.resolv.compiled._linuxffi_resolv.cpython-35m-x86_64-linux-gnu.so'
dropbox: load fq extension '/home/eater/.dropbox-dist/dropbox-lnx.x86_64-56.4.94/tornado.speedups.cpython-35m-x86_64-linux-gnu.so'
dropbox: load fq extension '/home/eater/.dropbox-dist/dropbox-lnx.x86_64-56.4.94/linuxffi.gnu.compiled._linuxffi_gnu.cpython-35m-x86_64-linux-gnu.so'
dropbox: load fq extension '/home/eater/.dropbox-dist/dropbox-lnx.x86_64-56.4.94/posixffi.libc._posixffi_libc.cpython-35m-x86_64-linux-gnu.so'
dropbox: load fq extension '/home/eater/.dropbox-dist/dropbox-lnx.x86_64-56.4.94/librsyncffi.compiled._librsyncffi.cpython-35m-x86_64-linux-gnu.so'
dropbox: load fq extension '/home/eater/.dropbox-dist/dropbox-lnx.x86_64-56.4.94/PyQt5.QtWebKit.cpython-35m-x86_64-linux-gnu.so'
dropbox: load fq extension '/home/eater/.dropbox-dist/dropbox-lnx.x86_64-56.4.94/PyQt5.QtCore.cpython-35m-x86_64-linux-gnu.so'
dropbox: load fq extension '/home/eater/.dropbox-dist/dropbox-lnx.x86_64-56.4.94/PyQt5.QtNetwork.cpython-35m-x86_64-linux-gnu.so'
dropbox: load fq extension '/home/eater/.dropbox-dist/dropbox-lnx.x86_64-56.4.94/PyQt5.QtGui.cpython-35m-x86_64-linux-gnu.so'
dropbox: load fq extension '/home/eater/.dropbox-dist/dropbox-lnx.x86_64-56.4.94/PyQt5.QtWebKitWidgets.cpython-35m-x86_64-linux-gnu.so'
dropbox: load fq extension '/home/eater/.dropbox-dist/dropbox-lnx.x86_64-56.4.94/PyQt5.QtWidgets.cpython-35m-x86_64-linux-gnu.so'
dropbox: load fq extension '/home/eater/.dropbox-dist/dropbox-lnx.x86_64-56.4.94/PyQt5.QtPrintSupport.cpython-35m-x86_64-linux-gnu.so'
dropbox: load fq extension '/home/eater/.dropbox-dist/dropbox-lnx.x86_64-56.4.94/PyQt5.QtDBus.cpython-35m-x86_64-linux-gnu.so'

[Lusil]

Hi there @eater!

Initially, although you mention that you’re running a Linux system, could you please let me know if you’re running a supported system? You can also find a full list of the system requirements to run the Dropbox  Linux installer here.

Furthermore, have you by any chance given the headless installation via command line a shot, maybe that will do the trick?

Let me know of any update! 

[eater]

Thanks, @Lusil. Yes, it's Ubuntu 18.04 with XFCE and Nautilus, which is listed as fully supported on that page.

And yes, I did try the headless installation as well, with the exact same results.

[Lusil]

Thanks for confirming this, @eater!

In this case, I’d kindly recommend giving an advanced reinstallation a try, since it’d remove any previous settings that may be causing any conflict to the app. It may just do the trick. 

If that doesn’t work either though, I’d kindly suggest continuing this discussion via email. For this reason, I can contact you via email to your email address associated with your Forum profile, or you can submit your request to our Support team. 

In any case, let me know how it goes! 

[eater]

Thanks, @Lusil. I did all that but still the same result.

[Lusil]

Thanks for confirming this, @eater. At this point in time, I’d recommend moving this discussion to email as account-specific info may be required to further investigate. 

I was able to locate your open request from my end and I can see that a specialized member of the team is reviewing it. I’ve made sure to pass your comments along to them. When they have more info on the matter they will get back to you. 

In the mean time, if you have any other questions, don’t hesitate to get back to us. Cheers! 

[Emanuele P.1]

Is there a known solution for this issue? It suddenly started the same behavior both for my laptopt (Ubuntu 18.10) and my wife's (Ubuntu 16.04 and, to try fixing it, Ubuntu 18.10).

In both cases the issue started when Dropbox had to sync a big amount of data (several dozens GB). It stopped syncing halfway, and started giving this problem every time after. Reinstalling Dropbox (from command line or software center, even deleting the hidden preference folders) doesn't solve it.

[Lusil]

Sorry to hear that, @Emanuele P.1. 

As a first step, could you please check if there are any third-party apps that might be blocking/hindering the syncing process, like an antivirus? Try temporarily disabling your antivirus or security program or configure your firewall to work with Dropbox; it just might do the trick. 

Also, could you by any chance be you connected through a work network? If you are, check with your company’s IT department, since there may be an update on your firewall settings (or another additional security precaution placed) which could be affecting your connection. 

Furthermore, do have a look through this article for more suggestions. Although the errors outlined may not apply to you, you may come across something that might help resolve your concern. 

If these don’t come up with any results, please check for any symlinks that may be the cause of this. You can check out this article (step 7) for more relevant details. 

If this comes to a dead-end too, please don’t hesitate to get back to me with more info, as well as a screenshot (omitting personal details) of the error message that you’re seeing or illustrating the behavior that you’re experiencing. 

Thanks in advance! 

[eater · Accepted solution]

Hi @Emanuele P.1. I went back and forth with the Dropbox engineering team for two months with no solution. Then I finally just randomly on my own tried removing the 10 or so symlinks that happened to be in my Dropbox directories, and that made it all start working normally again.

I see @Lusil gave you that suggestion, so maybe my experience has now made it into the Dropbox manual.

Hope that helps!

[Emanuele P.1]

I got the same issue after a fresh installation of Ubuntu 18.10, no additional apps installed.

I observe the same both from my home network and from my office network.

It could be related to some specific files (symbolic links for example) in my dropbox folder as suggested in point 7 of the guide you sent me. Indeed, in all the cases it broke when I was trying to do a quick backup to transfer data from an old computer to a new one, and I simply moved several folders in a Backup folder in Dropbox. There could be any kind of files.

However, since it does not sync, I cannot look for those files as suggested in the guide either.