I have a gallery 2.3.2 Site that randomly stopped working. Everything was fine for about a year, and nothing changed, but the index/main page decided to go blank.
I tried all sorts of things including debubbing, php and apache error log checks, but there were no errors.
It's a drupal embedded install, and stand-alone functionality was not disabled. Drupal had a direct link to the admin section of gallery, so I followed those links and it worked. I was also able to view albums from the sidebar menu that were working in the admin section, but still could not access the index/main page.
Finally I disabled most of the plugins in the gallery to see if one of them was causing the problem. The gallery started working again! Great, so now I can re-enable the plugins one-by-one to see which is causing the problem. I enabled all of the plugs and the site still worked. WTH??? I'm glad it's working now, but I find it odd that disabling and re-enabling the plugins is all it took to fix it.
Side note: the server was upgraded from Apache 2.2 to 2.4 around the time it stopped working. I don't know if that's related or not.