I have just bought and installed Zara theme along with the packaged plugins (no additional plugins where installed) on a clean OsCalss Install. All icons on the main page are displayed as small squares, screen shot attached.  Once I go into any of the categories, and go back to the main page, the icons are displayed., screen shot attached.
Website: ibayt.com

Try to disable all plugins. Do you use some adblock?

I disabled all plugins, yet icons are not displayed.  I tried using IE, Safari & Google Chrome where icons are not displayed till I click on a listing. Then the icons are displayed on listing details page. I click on home, the icons are then displayed on the main page (home).  The icons continue to show as long as the session is active.

@alsharif
It is caused by incorrectly set SSL on your osclass, please check their documentation. You can get error from console:
Access to Font at 'https://ibayt.com/oc-content/themes/zara/fonts/open-sans.woff' from origin 'http://ibayt.com' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'http://ibayt.com' is therefore not allowed access.
(index):1 Access to Font at 'https://ibayt.com/oc-content/themes/zara/fonts/fa/fonts/fontawesome-webfont.woff2?v=4.6.3' from origin 'http://ibayt.com' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'http://ibayt.com' is therefore not allowed access.
(index):1 Access to Font at 'https://ibayt.com/oc-content/themes/zara/fonts/OpenSans14.woff2' from origin 'http://ibayt.com' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'http://ibayt.com' is therefore not allowed access.
(index):1 Access to Font at 'https://ibayt.com/oc-content/themes/zara/fonts/OpenSans7.woff2' from origin 'http://ibayt.com' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'http://ibayt.com' is therefore not allowed access.
(index):1 Access to Font at 'https://ibayt.com/oc-content/themes/zara/fonts/fa/fonts/fontawesome-webfont.woff?v=4.6.3' from origin 'http://ibayt.com' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'http://ibayt.com' is therefore not allowed access.
(index):1 Access to Font at 'https://ibayt.com/oc-content/themes/zara/fonts/fa/fonts/fontawesome-webfont.ttf?v=4.6.3' from origin 'http://ibayt.com' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'http://ibayt.com' is therefore not allowed access.


Thank you Frosticek.  The SSL is corrected and the issue been resolved. You may mark it as resolved.