Hello Nathan,
Thanks for writing to us.
In case if you are using our bundled Revolution Slider plugin in that case the current compatible version is 6.4.2. You can check out our version compatibility page for more information. In case if you have purchased the separate licence of the Revolution Slider plugin from the slider author then you need to download the latest version of the slider plugin and updated it.
Please make sure you have a backup of your files and database before updating the theme and plugin. To be on the safe side I would suggest you take the slide backup as well.

For the icon font not rendering, it might be the issue of the plugin conflict or cache issue. I would suggest you troubleshoot with a few of the common issues before we investigate your settings.
- Testing for Plugin Conflict
- CSS/JS Customization
- Version Compatibility
- Disabling Cache
If it doesn’t work for you, please share your details in a secure note. Please provide the following details
- WordPress Login URL
- Admin level username and password
You can find the Secure Note button at the bottom of your posts
Thanks