Not sure if this is a Sigil 0.9.991 issue or an epubcheck plugin issue or a problem with the individual epubs.
- open epub in Sigil 0.9.18, run epubcheck plugin, validation completes
- open epub in Sigil 0.9.991, run epubcheck plugin, validation completes
- use Tools > Restructure Epub to Sigil Norm, run epubcheck plugin, plugin fails to complete with error message:
I have tested this on 10 different epubs — three epub2 and seven epub3.
The error occurred on 6 out of 10 epubs — 4 out of 7 EPUB3 and 2 out of 3 EPUB3.
I am on macOS High Sierra.
Any thoughts? Thank you