I add the vrt extension but it doesn't show up in the gallery, what next ?

VRTnetworkequipment_1.2.0-lo.oxt on Version:
Build ID: 1:5.2.3~rc2-0ubuntu1~xenial1
CPU Threads: 6; OS Version: Linux 4.4; UI Render: default;
Locale: en-GB (en_US.UTF-8); Calc: group

I am having this problem. What was the answer?

I ran into this issue today. After adding the package and restarting LibreOffice there was no VRT Extensions show in the Gallery, and if I tried to remove the extension from Extension Manager I was give an error to the effect of not being able to detect the type of the package. I removed the package manually from /home/{USER}/.config/libreoffice/4/user/uno_packages/cache/uno_packages and then re-installed using the Extension Manager. Immediately the gallery was working.