Thanks for replying and trying to help - I really appreciate it!
I'm on a Mac - OS X 10.6.8 / Sigil 0.6.2
I've closed everything else, I've tried Save As, but I'm still getting this message:
Error info: Cannot save file /Users/neil/Documents/Private 1/Fresher/20131217 American Freshman docs/20131217.epub: /Users/pdurrant/Documents/Projects/Sigil/Sigil-0.6.2-Code/src/Sigil/Misc/FontObfuscation.cpp(113): Throw in function void FontObfuscation::ObfuscateFile(const QString&, const QString&, const QString&)
Dynamic exception type: boost::exception_detail::clone_impl<FontObfuscatio nError>
std::exception::what: std::exception
[key*] = urn:uuid:460a0c04-b138-4d1a-b250-d5cf7cbc8c41
[algorithm*] =
http://www.idpf.org/2008/embedding
[font_filepath*] = /var/folders/VV/VV1vCjC3HzaoVQ-DTeXwf++++TI/-Tmp-/Sigil/scratchpad/8d4e4468-9b74-40c0-9e5b-110d63f68206/OEBPS/Fonts/PalatinoLinotype-Roman.ttf
Sigil version: 0.6.2
Runtime Qt: 4.8.3
Compiled Qt: 4.8.3
Platform: Mac SysInfo ID 8