When using the Panel's Update Function, it overwrites current HTACCESS file.
It would be helpful to either opt out of this file upon update or offer a merge and append to the current file, if different from previous build.
X3 Photo Gallery Support Forums
# ---------------------------------------------------------------------------
# X3 REQUIRED
# Below rewrite rules are strictly required by X3 for pages to work properly.
# Add custom rules inside "# custom rules start" and "# custom rules end" tags.
# ---------------------------------------------------------------------------
# custom rules start
(YOUR RULES HERE)
# custom rules end