Occasionally, cPanel will have a glitch and will load cPanel accounts, but with missing Icons. Like this:
If changing the theme doesn't work. Try the following:
Rebuild cPanel sprites.
Run the command:
/usr/local/cpanel/bin/rebuild_sprites -force -verbose
Redownload them from cPanel.
Go to /usr/local/cpanel/base/frontend
Mv paper_lantern paper_lantern_bak
The upcp script will download the theme files again and cPanel should load correctly now:
You can delete paper_lantern_bak once you can see it's working.