Dashboard "Themes" link never loads

I manually put a theme in the folder via my control panel, and I have done this a few times and I can never get the themes section to load on the dashboard to activate the theme. It just loads and loads and doesn’t do anything, I have got it to load once and that took like 10 mins and I couldn’t even activate the theme it justs loads and loads.

WHy is this? and what can I do to fix this?

my site is https://www.tektwo.net

p.s I have tried to do this on chromes and Firefox to see if it was a browser issue.