Edit an exported epub

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Hi,

I created an epub 3 with audio and text synchronization with Tobi. I exported it and it runs. But when I edit it with other editors like Sigil, for example to modify the cover or metadata (nothing related to the text or audio), then it doesn’t run anymore. What’s the problem?

Thanks

Sigil as far as I know does not fully support EPUB 3.

It is possible that after editing in Sigil, your file may not be a valid EPUB 3 anymore. if this is the case then media overlays will not work.

You may validate the file edited in Sigil at http://validator.idpf.org/

Ok, thank you!