Hi everyone,
Sorry if this has already been reported elsewhere, but I seem to have found a serious bug that is making Sigil pretty much unusable for producing a clean epub. I'm using version 0.8.901 on Windows 10 and it keeps messing up the html escape characters in my html documents. For example, when I open my html file in Sigil it changes an emdash ( &mdash

into — Unfortunately it's also doing the same to single double quotes and basically every html escape I have in my html file.
If I go into 'Preferences' and then 'Clean Source' and untick both the 'Open' and 'Save' boxes for automatically cleaning the html source, it makes no difference. If I correct the html escape codes and then save and close the epub, when I reopen it, it once again messes up all the html escape characters. Similarly, if I add all the html escape characters to the 'Preserve Entities' box that doesn't seem to make any difference either. Hope this information is helpful.
Paul