Не полностью поддерживает формат EPUB.

This is a good epub reader but I do wish that it could be configured as to whether or not previously read pages are listed in the browser's back button. (Right now it seems that they are with no option to disable that feature.)

Only thing i intensely dislike about this reader is that if you mess up and close the tab, or have a crash, and you don't recall which ePub you're reading, there's no way to go back to it. Surely there should be a way to write a local state file that would remember the previous opened file and position. Setting a bookmark is fine, but doesn't solve this issue.
If that were solved, it would be 5*.
The other issue is that if highlighting and selecting text, if you're heading towards the margin rather than away and you go a tad too far it will can it as a next/previous page activation, even though there is no click. Easy to recover from, but annoying.

It works well to open files from a web link (HTTP://...). However, if I try to open local files (local hard drive or local network), I get endless "open with..." dialogs.
I found a dirty fix : when I open a file from the web, the address always starts with "moz-extension://697be157-ddf5-4bbd-bd58-56b42dd47af5/reader.html", so I bookmarked this address, and it launches a "blank" epubreader interface, from there I can click the top gray "open" menu, so I can browse my local computer manually. It would be a lot nicer if I could just double-click files from Windows Explorer.

It would be nice to make use of the speech synthesizer capacities to read the book out loud with speed controls

проблема с кодировками текста

Lesen am PC ist sehr mühsam damit / Reading on PC is not easy

The earlier version is lovely - the lack of obvious links in the main page is a problem, the links to working versions may be there and it's possible I haven't seen them but this is part of the definition of 'no OBVIOUS' links! No add-on developer should be collaborating in this desire to herd the sheeple into auto-update braindeath, "Automatically update" == "oh yes master developer I trust you to run anything you like on my system anytime you feel like it" Or, in my case NOT.

Your earlier version is lovely, you should be making it obviously available and telling people that Firefox 52 ESR is perfectly functional, with none of the RUSTbucket crippling the Chrome-Crazy development team want to inflict!

All the good add-ons work ok on Firefox 52, if you get 52.2.0 then you may need to alter about:config to force it not to complain about version numbers (do a websearch!) but otherwise it's equally lovely.

An epub library interface is necessary!
For example, now i've to search the ebook in a directory full of other titles whenever is necessary to open it again. It's a little disgrace.
My solution:
- Install Firefox ESR 52.0 portable
- Install EPUBReader version 1.5.0.12
VOILÀ! Back to practicality.

界面太丑了

It used to be a great add-on till they changed it all.
Now you don't have a visible index on the left side like you used to have, you can't just switch to another chapter that easy anymore or see where you are at, you need to to go to the index button first to make the index visible and if you want to further read your last page you have to close the index again. It is not possible to see the index and the page you want to read simultaneously. A sidebar would be way better than an autohide bar or at least the choice between those two and not just the autohide bar this add-on has now. I also can't just click on a epub download and it opens automatically in the epubreader, instead I have to save it, go to firefox open the epubreader and then search for my book which is really annoying and not user friendly.
The older version is great and much more usable, this new one has too much flaws.

no search option