We've created this Forum Thread with some workarounds and advice to assist you in publishing you ebook.
"Experienced Unknown Issue" Error During Conversion
I am trying to convert my Libre Office .odt file to an epub. I have done small samples of my book as I've been working on it and received feedback during the conversion process as expected.
Yesterday I tried to upload my entire book. I continue to get the error below. I have no idea what the issue is for me to fix. I've read the guide and think I am in compliance with everything. Does anyone have any suggestions?