hmmm. At first I was like BINGO! downgrading PHP from 7.4 to 7.3 fixed the issue and was able to view the page
https://gallery.butzbach.net
However, when I went back into \panel and tried to log in, the page just refreshed back to the login page and wouldn't let me in. Curiously I moved PHP back up to 7.4, I could log back into \panel, AND the site was still working??? Seems this was a 'turn it off and back on' episode - but that does not tell me what went wrong to fix the issue.
I'm not sure if I should keep looking for what went wrong or just take it as a workaround and say it's fixed. I had '
http://galleryproject.org/' years ago with PHP 5.3 but it got frustrated when I had to fix it everytime PHP came out with a new version, and stopped using a gallery altogether. If you're wondering I Googled "PHP 7 Gallery" to find this gallery compatible with 7. And thank you!
** UPDATE: Installed a second Full version demo at
https://butzbach.net/gallery2 - same issue, resolved by down/up-grading PHP. In addition to this confusion, went back to the first gallery and made a change (hid the lalala page). Went back to view gallery and it had the spinning circle again. Toggled PHP, nothing happened. about a minute later I refreshed page and it started working. Same thing when I add pictures, just have to toggle PHP. Will make more changes and try some different things.