Could not connect to host (http://localhost:18083/) -- Ubuntu Serve 16.04, Vbox 5.1.18

[gurabli]

Hi,
Everything was working fine, and after now upgrading to 5.1.18 I get the Could not connect to host (http://localhost:18083/) error. Really don't know what to do. Any ideas? Thanks!

[Michael Wills]

I had this generic message too.

In case anyone else runs into the issue I experienced, it looks like after the upgrade, VirtualBox spun up multiple instances of the webserver daemon. To resolve I:

Manually killed all instances of the VirtualBox webserver

sudo pkill vboxwebsrv

Restarted the webserver daemon through systemd

sudo systemctl restart vboxweb-service.service

After this I had only one instance running of the webserver

$ ps -ef | grep web
vboxadm+  2450     1  0 12:52 ?        00:00:00 /usr/lib/virtualbox/vboxwebsrv --background
$ 

At this point I was able to log in through the phpVirtualBox interface.