Originally Posted by boatat72
In 64 bit it is turned on by default and there is no "Preferences" button to turn it off...
yes there is - edit - preferences... or simply f5 - all clean source options are there
now if ( in 64 bit) I untick all cleaning options & set pretty print to OFF, & then reload your test epub - it is still OK, as before..
maybe that helps narrow things down further ?