I probably didn't name the config option correctly. Thank you, I'll look into it.

The config exists. Are you sure you didn't remove the galleries addon or that the setup wizard didn't accidentally remove it?

NVM I found the issue looking at the stack trace your site sent in telemetry

Automated response: Config option homepage_slider_enabled referenced but does not exist

Config option homepage_slider_enabled referenced but does not exist

This happens because gallery addon was uninstalled, yet Tempcode was evaluating the addon check and the config option together. This should have been a nested IF directive, only checking the theme option if gallery is installed.

A hotfix (a TAR of files to upload) has been uploaded to this issue. These files are made to the latest intra-version state (i.e. may roll in earlier fixes too if made to the same files) - so only upload files newer than what you have already. If there are files in a hot-fix that you don't have then they probably relate to addons that you don't have installed and should be skipped. Always take backups of files you are replacing or keep a copy of the manual installer for your version, and only apply fixes you need. These hotfixes are not necessarily reliable or well supported. Not sure how to extract TAR files to your Windows computer? Try 7-zip (http://www.7-zip.org/).