Hi!

I'm hosting a piwigo in a podman container. I'm not exactly sure what version I'm running, but it's whatever is pulled down with lscr.io/linuxserver/piwigo:latest. LinuxServer.io implies it's probably version 15.6.0-ls318

When I initially set it up, I was able to get to the admin page, although at the time I was using the ip address rather than the domain name. I'm not sure if I ever tried the admin page via domain name, so I'm not sure if that was working or not.

Domain name is working correctly for the website, and I am pretty happy with how the public end of my website looks/works.

However, now, when I try to go to the admin.php page, I am consistently getting a 502 Bad Gateway error, regardless of whether I use the Domain Name or IP Address/port.

The PHP logs for piwigo do not show anything useful, but when I attempt to load the admin page, I get the following errors in piwigo's nginx logs:

025/10/31 20:09:55 [error] 254#254: *11 FastCGI sent in stderr: "PHP message: PHP Warning:  Undefined array key "meta_ref_enabled" in /config/www/_data/templates_c/1yju0id^31d431bc39caa6c246e67d7bc85814c64f53de6c_0.file.header.tpl.php on line 39; PHP message: PHP Warning:  Attempt to read property "value" on null in /config/www/_data/templates_c/1yju0id^31d431bc39caa6c246e67d7bc85814c64f53de6c_0.file.header.tpl.php on line 39; PHP message: PHP Warning:  Undefined array key "theme_config" in /config/www/_data/templates_c/1yju0id^31d431bc39caa6c246e67d7bc85814c64f53de6c_0.file.header.tpl.php on line 128; PHP message: PHP Warning:  Attempt to read property "value" on null in /config/www/_data/templates_c/1yju0id^31d431bc39caa6c246e67d7bc85814c64f53de6c_0.file.header.tpl.php on line 128; PHP message: PHP Warning:  Attempt to read property "bootstrap_theme" on null in /config/www/_data/templates_c/1yju0id^31d431bc39caa6c246e67d7bc85814c64f53de6c_0.file.header.tpl.php on line 128; PHP message: PHP Warning:  Undefined array key "theme_config" in /config/www/_data/templates_c/1yju0id^31d431bc39caa6c246e67d7bc85814c64f53de6c_0.file.header.tpl.php on line 135; PHP message: PHP Warning:  Attempt to read property "value" on null in /config/www/_data/templates_c/1yju0id^31d431bc39caa6c246e67d7bc85814c64f53de6c_0.file.header.tpl.php on line 135; PHP message: PHP Warning:  Attempt to read property "bootstrap_theme" on null in /config/www/_data/templates_c/1yju0id^31d431bc39caa6c246e67d7bc85814c64f53de6c_0.file.header.tpl.php on line 135; PHP message: PHP Warning:  Undefined array key "theme_config" in /config/www/_data/templates_c/1yju0id^31d431bc39caa6c246e67d7bc85814c64f53de6c_0.file.header.tpl.php on line 135; PHP message: PHP Warning:  Attempt to read property "value" on null in /config/www/_data/templates_c/1yju0id^31d431bc39caa6c246e67d7bc85814c64f53de6c_0.file.header.tpl.php on line 135; PHP message: PHP Warning:  Attempt to read property "bootstrap_theme" on null in /config/www/_data/templates_c/1yju0id^31d431bc39caa6
2025/10/31 20:09:55 [error] 254#254: *11 FastCGI sent in stderr: "c85814c64f53de6c_0.file.header.tpl.php on line 167; PHP message: PHP Warning:  Attempt to read property "bootstrap_theme" on null in /config/www/_data/templates_c/1yju0id^31d431bc39caa6c246e67d7bc85814c64f53de6c_0.file.header.tpl.php on line 167; PHP message: PHP Deprecated:  preg_match(): Passing null to parameter #2 ($subject) of type string is deprecated in /config/www/_data/templates_c/1yju0id^31d431bc39caa6c246e67d7bc85814c64f53de6c_0.file.header.tpl.php on line 167; PHP message: PHP Warning:  Undefined array key "theme_config" in /config/www/_data/templates_c/1yju0id^31d431bc39caa6c246e67d7bc85814c64f53de6c_0.file.header.tpl.php on line 357; PHP message: PHP Warning:  Attempt to read property "value" on null in /config/www/_data/templates_c/1yju0id^31d431bc39caa6c246e67d7bc85814c64f53de6c_0.file.header.tpl.php on line 357; PHP message: PHP Warning:  Attempt to read property "page_header" on null in /config/www/_data/templates_c/1yju0id^31d431bc39caa6c246e67d7bc85814c64f53de6c_0.file.header.tpl.php on line 357; PHP message: PHP Warning:  Undefined array key "theme_config" in /config/www/_data/templates_c/1yju0id^41418a2f246909bfd4bed5e5a2aa65e1deca6e21_0.file.redirect.tpl.php on line 24; PHP message: PHP Warning:  Attempt to read property "value" on null in /config/www/_data/templates_c/1yju0id^41418a2f246909bfd4bed5e5a2aa65e1deca6e21_0.file.redirect.tpl.php on line 24; PHP message: PHP Warning:  Attempt to read property "fluid_width" on null in /config/www/_data/templates_c/1yju0id^41418a2f246909bfd4bed5e5a2aa65e1deca6e21_0.file.redirect.tpl.php on line 24; PHP message: PHP Warning:  Undefined array key "theme_config" in /config/www/_data/templates_c/1yju0id^41418a2f246909bfd4bed5e5a2aa65e1deca6e21_0.file.redirect.tpl.php on line 29; PHP message: PHP Warning:  Attempt to read property "value" on null in /config/www/_data/templates_c/1yju0id^41418a2f246909bfd4bed5e5a2aa65e1deca6e21_0.file.redirect.tpl.php on line 29; PHP message: PHP Warning:
2025/10/31 20:09:55 [error] 254#254: *11 upstream sent too big header while reading response header from upstream, client: 10.89.2.27, server: _, request: "GET /admin.php HTTP/1.0", upstream: "fastcgi://127.0.0.1:9000", host: "liquidfortress.com"

I haven't made any changes to the code of piwigo. Initially when I started getting the 502 bad gateway error, I had changed *nothing* from when it was working after initial setup last week. I have since attempted updating with podman pull, in the hopes that maybe there was a bug that had since been fixed.

I am noticing that this error does appear to have something to do with bootstrap-darkroom theme, which I am using. But, I'm not really sure what's causing the issues. I am trying to look through the php files with the errors, but I'm not seeing anything immediately obvious, and I'm not getting any useful hits on google.

Thank you for the help!
~LF