Won't install on Ubuntu 16.04

[teo8976]

I downloaded the package for Ubuntu 16.04 from ​http://download.virtualbox.org/virtualbox/5.1.28/virtualbox-5.1_5.1.28-117968~Ubuntu~xenial_amd64.deb

By double-clicking on it it opens with Ubuntu Software Whatever, an "install" button shows up. That doesn't work, ​https://forums.virtualbox.org/viewtopic.php?f=1&t=84623&sid=255ddb223689adba4a433f51a9e7500d&p=401997#p401997it just shows a progress bar for a fraction of a second and then the button appears again, it does nothing, gives no error message. But that probably is a bug in Ubuntu.

So in a terminal I did:

$ sudo apt install ./virtualbox-5.1_5.1.28-117968-Ubuntu-xenial_amd64.deb 

And this is the output:

Reading package lists... Done
Building dependency tree       
Reading state information... Done
Note, selecting 'virtualbox-5.1' instead of './virtualbox-5.1_5.1.28-117968-Ubuntu-xenial_amd64.deb'
The following packages were automatically installed and are no longer required:
  fonts-horai-umefont fonts-unfonts-core libgif7:i386
  libp11-kit-gnome-keyring:i386 linux-headers-4.4.0-79
  linux-headers-4.4.0-79-generic linux-headers-4.4.0-83
  linux-headers-4.4.0-83-generic linux-headers-4.4.0-89
  linux-headers-4.4.0-89-generic linux-headers-4.4.0-91
  linux-headers-4.4.0-91-generic linux-image-4.4.0-79-generic
  linux-image-4.4.0-83-generic linux-image-4.4.0-89-generic
  linux-image-4.4.0-91-generic linux-image-extra-4.4.0-79-generic
  linux-image-extra-4.4.0-83-generic linux-image-extra-4.4.0-89-generic
  linux-image-extra-4.4.0-91-generic linux-signed-image-4.4.0-79-generic
  linux-signed-image-4.4.0-83-generic linux-signed-image-4.4.0-89-generic
  linux-signed-image-4.4.0-91-generic ocl-icd-libopencl1:i386 odbcinst
  odbcinst1debian2 p11-kit-modules:i386 p7zip unixodbc wine-gecko2.21
  wine-gecko2.21:i386 wine-mono0.0.8 winetricks
Use 'sudo apt autoremove' to remove them.
The following additional packages will be installed:
  libsdl-ttf2.0-0
The following NEW packages will be installed:
  libsdl-ttf2.0-0 virtualbox-5.1
0 upgraded, 2 newly installed, 0 to remove and 10 not upgraded.
Need to get 0 B/66,0 MB of archives.
After this operation, 163 MB of additional disk space will be used.
Do you want to continue? [Y/n] y
Get:1 /home/teo/Downloads/virtualbox-5.1_5.1.28-117968-Ubuntu-xenial_amd64.deb virtualbox-5.1 amd64 5.1.28-117968~Ubuntu~xenial [65,9 MB]
Preconfiguring packages ...
Selecting previously unselected package libsdl-ttf2.0-0:amd64.
(Reading database ... 454844 files and directories currently installed.)
Preparing to unpack .../libsdl-ttf2.0-0_2.0.11-3_amd64.deb ...
Unpacking libsdl-ttf2.0-0:amd64 (2.0.11-3) ...
Selecting previously unselected package virtualbox-5.1.
Preparing to unpack .../virtualbox-5.1_5.1.28-117968-Ubuntu-xenial_amd64.deb ...
Unpacking virtualbox-5.1 (5.1.28-117968~Ubuntu~xenial) ...
Processing triggers for systemd (229-4ubuntu19) ...
Processing triggers for ureadahead (0.100.0-19) ...
Processing triggers for hicolor-icon-theme (0.15-0ubuntu1) ...
Processing triggers for shared-mime-info (1.5-2ubuntu0.1) ...
Unknown media type in type 'all/all'
Unknown media type in type 'all/allfiles'
Processing triggers for desktop-file-utils (0.22-1ubuntu5.1) ...
Processing triggers for bamfdaemon (0.5.3~bzr0+16.04.20160824-0ubuntu1) ...
Rebuilding /usr/share/applications/bamf-2.index...
Processing triggers for mime-support (3.59ubuntu1) ...
Processing triggers for gnome-menus (3.13.3-6ubuntu3.1) ...
Setting up libsdl-ttf2.0-0:amd64 (2.0.11-3) ...
Setting up virtualbox-5.1 (5.1.28-117968~Ubuntu~xenial) ...
addgroup: The group `vboxusers' already exists as a system group. Exiting.
depmod: ERROR: could not open directory /lib/modules/3.19.0-30-generic: No such file or directory
depmod: FATAL: could not search modules: No such file or directory
depmod: ERROR: could not open directory /lib/modules/3.8.0-19-generic: No such file or directory
depmod: FATAL: could not search modules: No such file or directory
depmod: ERROR: could not open directory /lib/modules/4.2.0-30-generic: No such file or directory
depmod: FATAL: could not search modules: No such file or directory
Processing triggers for libc-bin (2.23-0ubuntu9) ...