If I use calibre to do an ePub to ePub conversion on an ePub that has embedded fonts that are obfuscated with Adobe's font-mangling scheme... the resulting ePub doesn't work properly in ADE (Desktop 126.96.36.1991). The embedded fonts are ignored/not used. Using Tweak Book to simply add the "urn:uuid:" prefix before the uuid string in the OPF file that calibre produces allowed ADE to properly display the embedded fonts.
I saw there was an old bug about this
, but at that time, it was decided that "calibre generated epubs with obfuscated fonts work fine with ADE."
This no longer seems to be the case. ADE certainly seems to be looking for that "urn:uuid:" prefix.
using calibre v0.8.38 - 0.8.43. Added a bug-report (#957527) with an attached epub and steps to recreate the issue. The bug report needed to be marked "Private" unfortunately.