pkg: cached package wxMaxima-17.05.1: size mismatch, cannot continue

[AN]

Hi:

FreeBSD FBSD_12 12.0-CURRENT FreeBSD 12.0-CURRENT #3 r330356: Sat Mar  3 
20:44:35 EST 2018 
root at FBSD_12:/usr/obj/usr/src/amd64.amd64/sys/MYKERNEL  amd64 1200059

I recently started having a problem when trying to install a package:

# pkg install wxmaxima
Updating FreeBSD repository catalogue...
FreeBSD repository is up to date.
All repositories are up to date.
The following 6 package(s) will be affected (of 0 checked):

New packages to be INSTALLED:
 	wxMaxima: 17.05.1
 	atkmm: 2.24.2_1
 	maxima: 5.41.0
 	gnuplot: 5.2.2_1
 	wx28-gtk2: 2.8.12_7
 	wx28-gtk2-common: 2.8.12_7

Number of packages to be installed: 6

The process will require 146 MiB more space.
34 MiB to be downloaded.

Proceed with this action? [y/N]: y
[1/6] Fetching wxMaxima-17.05.1.txz: 100%    3 MiB   2.9MB/s    00:01
pkg: cached package wxMaxima-17.05.1: size mismatch, fetching from remote
[2/6] Fetching wxMaxima-17.05.1.txz: 100%    3 MiB   2.9MB/s    00:01
pkg: cached package wxMaxima-17.05.1: size mismatch, cannot continue


Any help fixing this would be greatly appreciated.  Thanks in advance.