My version on php is : 5.6.63
My version of calibre (Mac OS) is 3.23.0 (latest AFAIK)
My version of COPS is 1.1.1 (copied form GitHub)
Reminder :
I have done some testing of my issue regarding the fact that I can't go beyond the summary page of a custom field (please refer to the picture I attached to post #1638)
Mac OS - LAN access - HTML - Safari : does not work (rolling beans)

Mac OS - LAN access - HTML - Google Chrome : does not work (rolling beans)

Mac OS - LAN access - HTML - Firefox : does not work (rolling beans)

iOS (iPhone/iPad) - LAN access - HTML - iOS browser : does not work

(blank/gray page)

iOS (iPhone/iPad) -
WAN access - HTML - iOS browser : does not work (blank/gray page)
but :
iOS (iPhone and iPad) - WAN access -
FEED (
http://[MYIP]/COPS/feed.php) -
eBook Search app :
WORKS !
So what do you think is going wrong ?