I was about to board a flight so I quickly visited a succession of webpages, allowed them to fully load, and added them to the reading list on my Firefox for iPad. Sadly, while in airplane mode, when I went to open the pages from the reading list, they all said “Loading content...” and, after a delay, “The page could not be displayed in reader view.” If I click the link to load original page it just tells me that i’m Offline.

Going back now that i’m online, these pages can in fact be loaded in reader view. Somehow the browser just seems unable to do it while offline. In experimenting, it looks like it will work if you load the page, and turn on reader view first before adding to the reading list. But this seems to be a bug and should be fixed. The user shouldn’t need to load reader view before adding to the reading list for offline viewing.