Firefox update issue

[MR ZenWiz]

I don't know if this is actually a problem or not.

Running an update (sudo apt-get dist-upgrade) on Xubuntu 16.04, I got
these messages during the update, but everything appears to be
installed and working.  Just wondering what these mean:

Preparing to unpack .../firefox_51.0.1+build2-0ubuntu0.16.04.2_amd64.deb ...
Traceback (most recent call last):
  File "/usr/bin/lsb_release", line 25, in <module>
    import lsb_release
ImportError: No module named 'lsb_release'
Traceback (most recent call last):
  File "/usr/bin/lsb_release", line 25, in <module>
    import lsb_release
ImportError: No module named 'lsb_release'
/var/lib/dpkg/tmp.ci/preinst: 61: [: Illegal number:

???

Thanks.
MR