I have Ubuntu X64 16.04 on my system. This was an upgrade from 15.10. The upgrade was successful, but now I am unable to see Nautilus in in alt-tab and an already opened instance cannot be seen. Because of this, I have to open a new instance every time. Kinda tedious as if I have some location opened, it's forgotten as soon as I go in some other app. Check out the screenshot. As you can see in the screenshot, in the left side menu, there are always these small white arrows which indicate the app is open, but it does not happen with Nautilus.
I have tried to purge nautilis, reinstall it, then drag-dropped it from applications, but as soon as I quit Nautilus, the same problem is back again.
Any help would be nice. Thank you.
Update
Output for killall nautilus && nautilus
Initializing nautilus-dropbox 2015.10.28
Nautilus-Share-Message: Called "net usershare info" but it failed: 'net usershare' returned error 255: mkdir failed on directory /var/run/samba/msg.lock: Permission denied
net usershare: cannot open usershare directory /var/lib/samba/usershares. Error No such file or directory
Please ask your system administrator to enable user sharing.
killall nautilus && nautilus? Does the problem happen also for the guest user? – Andrea Lazzarotto Aug 18 '16 at 08:27