Ozzie Isaacs

Okay, got it now. This is done via pure javascript, so please open the developer console on your browser and check for any javascript errors there. -> You are using...

Has to be an old version, currently web.py only has approx. 1500 lines. The line throwing the exception is no longer in code

It's merged to the newest nightly version

Here are some hints on how to deal with it: https://github.com/janeczku/calibre-web/issues/1466

I can reproduce it. I'll have a look at it.

Please update to the newest nightly build, it's working there.

Admin section -> Basic configuration -> server configuration -> update channel -> switch to nightly Back to admin section -> search for update -> update

It‘s currently not possible: https://github.com/janeczku/calibre-web/wiki/Command-Line-Interface#environmental-variables

The Mozilla reader is already used: https://github.com/janeczku/calibre-web/blob/master/cps/static/js/libs/pdf.js The pdf in use, has to support this feature also

I updated pdf.js to a more recent version in the nightly version of calibre-web, please feel free to test it (I don't expect any change)