[GregTheGrate]

I recently downloaded a book with non-displayable characters in it. Kindle White shows the Unicode in a box. Unfortunately I couldn't see these codes in the editor and had to use Sigil to fix the text.

The Calibre editor seemed to have ignored the non-displayable characters in both panes.

Is there an option I should be setting so that I can see these letters so that I am able to replace them. They are typlically the left and right-quotes, apostrophe and em-dash.

Sigil displays them as a question mark in a box.

Many thanks