Hello and Hi

I've installed the Bootstrap Darkroom theme, but the navigation icons (all the icons) display only as little boxes. I've tried looking for the issue, but I can't find what's wrong. I really do want to use the theme--it's the best for my site. Any ideas of how I can fix this? I have searched the forum with no luck.

Thanks,
CJS

Piwigo 12.2.0 Check for upgrade
Operating system: WINNT
PHP: 7.4.27 (Show info) [2022-02-03 21:01:06]
MySQL: 5.5.5-10.3.32-MariaDB [2022-02-03 13:01:06]
Graphics Library: GD bundled (2.1.0 compatible)
Cache size N/A   never calculated Refresh
Activated plugin list2
LocalFiles Editor
RV Thumb Scroller