I was wondering, when I update things I often get messages that say:

Unknown media type in type 'all/all'
Unknown media type in type 'all/allfiles'
Unknown media type in type 'uri/mms'
Unknown media type in type 'uri/mmst'
Unknown media type in type 'uri/mmsu'
Unknown media type in type 'uri/pnm'
Unknown media type in type 'uri/rtspt'
Unknown media type in type 'uri/rtspu'

and messages such as those. Why do I get them? It appears not to matter as
everything completes successfully.
-- 
:-)~MIKE~(-:

(output in terminal during upgrade example)
Unpacking virtualbox-guest-dkms (4.3.34-dfsg-1+deb8u1ubuntu1.14.04.1) over
(4.3.18-dfsg-1~ubuntu1~trusty1) ...
Preparing to unpack .../archives/inxi_1.9.17-1_all.deb ...
Unpacking inxi (1.9.17-1) over (1.8.4-1) ...
Processing triggers for man-db (2.6.7.1-1ubuntu1) ...
Processing triggers for ureadahead (0.100.0-16) ...
ureadahead will be reprofiled on next reboot
Processing triggers for cups (1.7.2-0ubuntu1.6) ...
Processing triggers for hicolor-icon-theme (0.13-1) ...
Processing triggers for shared-mime-info (1.2-0ubuntu3) ...
Unknown media type in type 'all/all'
Unknown media type in type 'all/allfiles'
Unknown media type in type 'uri/mms'
Unknown media type in type 'uri/mmst'
Unknown media type in type 'uri/mmsu'
Unknown media type in type 'uri/pnm'
Unknown media type in type 'uri/rtspt'
Unknown media type in type 'uri/rtspu'
Processing triggers for mime-support (3.54ubuntu1.1) ...
Processing triggers for desktop-file-utils (0.22-1ubuntu1) ...
Setting up libssl1.0.0:i386 (1.0.1f-1ubuntu2.16) ...
Setting up libssl1.0.0:amd64 (1.0.1f-1ubuntu2.16) ...
Setting up libcupsfilters1:amd64 (1.0.52-0ubuntu1.6) ...
Setting up libfontembed1:amd64 (1.0.52-0ubuntu1.6) ...
Setting up libsndfile1:amd64 (1.0.25-7ubuntu2.1) ...
Setting up libsndfile1:i386 (1.0.25-7ubuntu2.1) ...
Setting up openssl (1.0.1f-1ubuntu2.16) ...
Setting up cups-browsed (1.0.52-0ubuntu1.6) ...
cups-browsed start/running, process 31502
Setting up cups-filters-core-drivers (1.0.52-0ubuntu1.6) ...
Setting up cups-filters (1.0.52-0ubuntu1.6) ...
.
Setting up virtualbox-dkms (4.3.34-dfsg-1+deb8u1ubuntu1.14.04.1) ...
Loading new virtualbox-4.3.34 DKMS files...
Building only for 3.13.0-37-generic
Building initial module for 3.13.0-37-generic
Done.