@Kroeber I can download the ebook from my blog but the generated ePub file doesn’t validate and Google Play Books rejects it with an error. For example, the Draft2Digital ePub validator returns a thick wall of errors:
ERROR(RSC-005): .tmp.tmpfjo5g478.epub/EPUB.package.opf(8,24): Error while parsing file: character content of element "dc:date" invalid; must be a string with length at least 1 (actual length was 0)
ERROR(CSS-001): .tmp.tmpfjo5g478.epub/EPUB.css.epub.css(1,405): The 'unicode-bidi' property must not be included in an EPUB Style Sheet.
ERROR(RSC-005): .tmp.tmpfjo5g478.epub/EPUB.xhtml.section0024.xhtml(38,20): Error while parsing file: attribute "align" not allowed here; expected attribute "about", "accesskey", "aria-activedescendant", "aria-atomic", "aria-autocomplete", "aria-busy", "aria-checked", "aria-colcount", "aria-colindex", "aria-colspan", "aria-controls", "aria-current", "aria-describedby", "aria-details", "aria-disabled", "aria-dropeffect", "aria-errormessage", "aria-expanded", "aria-flowto", "aria-grabbed", "aria-haspopup", "aria-hidden", "aria-invalid", "aria-keyshortcuts", "aria-label", "aria-labelledby", "aria-level", "aria-live", "aria-modal", "aria-multiline", "aria-multiselectable", "aria-orientation", "aria-owns", "aria-placeholder", "aria-posinset", "aria-pressed", "aria-readonly", "aria-relevant", "aria-required", "aria-roledescription", "aria-rowcount", "aria-rowindex", "aria-rowspan", "aria-selected", "aria-setsize", "aria-sort", "aria-valuemax", "aria-valuemin", "aria-valuenow", "aria-valuetext", "autocapitalize", "class", "colspan", "content", "contenteditable", "datatype", "dir", "draggable", "headers", "hidden", "id", "inlist", "is", "itemid", "itemprop", "itemref", "itemscope", "itemtype", "lang", "ns1:type", "ns2:alphabet", "ns2:ph", "onabort", "onautocomplete", "onautocompleteerror", "onblur", "oncancel", "oncanplay", "oncanplaythrough", "onchange", "onclick", "onclose", "oncontextmenu", "oncuechange", "ondblclick", "ondrag", "ondragend", "ondragenter", "ondragexit", "ondragleave", "ondragover", "ondragstart", "ondrop", "ondurationchange", "onemptied", "onended", "onerror", "onfocus", "onfocusin", "onfocusout", "oninput", "oninvalid", "onkeydown", "onkeypress", "onkeyup", "onload", "onloadeddata", "onloadedmetadata", "onloadstart", "onmousedown", "onmouseenter", "onmouseleave", "onmousemove", "onmouseout", "onmouseover", "onmouseup", "onpause", "onplay", "onplaying", "onprogress", "onratechange", "onreset", "onresize", "onscroll", "onseeked", "onseeking", "onselect", "onsort", "onstalled", "onsubmit", "onsuspend", "ontimeupdate", "ontoggle", "onvolumechange", "onwaiting", "onwheel", "prefix", "property", "rel", "resource", "rev", "role", "rowspan", "scope", "slot", "spellcheck", "style", "tabindex", "title", "translate", "typeof", "vocab", "xml:base", "xml:lang" or "xml:space" (with xmlns:ns1="http://www.idpf.org/2007/ops" xmlns:ns2="http://www.w3.org/2001/10/synthesis")
ERROR(RSC-005): .tmp.tmpfjo5g478.epub/EPUB.xhtml.section0024.xhtml(39,20): Error while parsing file: attribute "align" not allowed here; expected attribute "about", "accesskey", "aria-activedescendant", "aria-atomic", "aria-autocomplete", "aria-busy", "aria-checked", "aria-colcount", "aria-colindex", "aria-colspan", "aria-controls", "aria-current", "aria-describedby", "aria-details", "aria-disabled", "aria-dropeffect", "aria-errormessage", "aria-expanded", "aria-flowto", "aria-grabbed", "aria-haspopup", "aria-hidden", "aria-invalid", "aria-keyshortcuts", "aria-label", "aria-labelledby", "aria-level", "aria-live", "aria-modal", "aria-multiline", "aria-multiselectable", "aria-orientation", "aria-owns", "aria-placeholder", "aria-posinset", "aria-pressed", "aria-readonly", "aria-relevant", "aria-required", "aria-roledescription", "aria-rowcount", "aria-rowindex", "aria-rowspan", "aria-selected", "aria-setsize", "aria-sort", "aria-valuemax", "aria-valuemin", "aria-valuenow", "aria-valuetext", "autocapitalize", "class", "colspan", "content", "contenteditable", "datatype", "dir", "draggable", "headers", "hidden", "id", "inlist", "is", "itemid", "itemprop", "itemref", "itemscope", "itemtype", "lang", "ns1:type", "ns2:alphabet", "ns2:ph", "onabort", "onautocomplete", "onautocompleteerror", "onblur", "oncancel", "oncanplay", "oncanplaythrough", "onchange", "onclick", "onclose", "oncontextmenu", "oncuechange", "ondblclick", "ondrag", "ondragend", "ondragenter", "ondragexit", "ondragleave", "ondragover", "ondragstart", "ondrop", "ondurationchange", "onemptied", "onended", "onerror", "onfocus", "onfocusin", "onfocusout", "oninput", "oninvalid", "onkeydown", "onkeypress", "onkeyup", "onload", "onloadeddata", "onloadedmetadata", "onloadstart", "onmousedown", "onmouseenter", "onmouseleave", "onmousemove", "onmouseout", "onmouseover", "onmouseup", "onpause", "onplay", "onplaying", "onprogress", "onratechange", "onreset", "onresize", "onscroll", "onseeked", "onseeking", "onselect", "onsort", "onstalled", "onsubmit", "onsuspend", "ontimeupdate", "ontoggle", "onvolumechange", "onwaiting", "onwheel", "prefix", "property", "rel", "resource", "rev", "role", "rowspan", "scope", "slot", "spellcheck", "style", "tabindex", "title", "translate", "typeof", "vocab", "xml:base", "xml:lang" or "xml:space" (with xmlns:ns1="http://www.idpf.org/2007/ops" xmlns:ns2="http://www.w3.org/2001/10/synthesis")
ERROR(RSC-005): .tmp.tmpfjo5g478.epub/EPUB.xhtml.section0024.xhtml(45,20): Error while parsing file: attribute "align" not allowed here; expected attribute "about", "accesskey", "aria-activedescendant", "aria-atomic", "aria-autocomplete", "aria-busy", "aria-checked", "aria-colcount", "aria-colindex", "aria-colspan", "aria-controls", "aria-current", "aria-describedby", "aria-details", "aria-disabled", "aria-dropeffect", "aria-errormessage", "aria-expanded", "aria-flowto", "aria-grabbed", "aria-haspopup", "aria-hidden", "aria-invalid", "aria-keyshortcuts", "aria-label", "aria-labelledby", "aria-level", "aria-live", "aria-modal", "aria-multiline", "aria-multiselectable", "aria-orientation", "aria-owns", "aria-placeholder", "aria-posinset", "aria-pressed", "aria-readonly", "aria-relevant", "aria-required", "aria-roledescription", "aria-rowcount", "aria-rowindex", "aria-rowspan", "aria-selected", "aria-setsize", "aria-sort", "aria-valuemax", "aria-valuemin", "aria-valuenow", "aria-valuetext", "autocapitalize", "class", "colspan", "content", "contenteditable", "datatype", "dir", "draggable", "headers", "hidden", "id", "inlist", "is", "itemid", "itemprop", "itemref", "itemscope", "itemtype", "lang", "ns1:type", "ns2:alphabet", "ns2:ph", "onabort", "onautocomplete", "onautocompleteerror", "onblur", "oncancel", "oncanplay", "oncanplaythrough", "onchange", "onclick", "onclose", "oncontextmenu", "oncuechange", "ondblclick", "ondrag", "ondragend", "ondragenter", "ondragexit", "ondragleave", "ondragover", "ondragstart", "ondrop", "ondurationchange", "onemptied", "onended", "onerror", "onfocus", "onfocusin", "onfocusout", "oninput", "oninvalid", "onkeydown", "onkeypress", "onkeyup", "onload", "onloadeddata", "onloadedmetadata", "onloadstart", "onmousedown", "onmouseenter", "onmouseleave", "onmousemove", "onmouseout", "onmouseover", "onmouseup", "onpause", "onplay", "onplaying", "onprogress", "onratechange", "onreset", "onresize", "onscroll", "onseeked", "onseeking", "onselect", "onsort", "onstalled", "onsubmit", "onsuspend", "ontimeupdate", "ontoggle", "onvolumechange", "onwaiting", "onwheel", "prefix", "property", "rel", "resource", "rev", "role", "rowspan", "slot", "spellcheck", "style", "tabindex", "title", "translate", "typeof", "vocab", "xml:base", "xml:lang" or "xml:space" (with xmlns:ns1="http://www.idpf.org/2007/ops" xmlns:ns2="http://www.w3.org/2001/10/synthesis")
ERROR(RSC-005): .tmp.tmpfjo5g478.epub/EPUB.xhtml.section0024.xhtml(46,20): Error while parsing file: attribute "align" not allowed here; expected attribute "about", "accesskey", "aria-activedescendant", "aria-atomic", "aria-autocomplete", "aria-busy", "aria-checked", "aria-colcount", "aria-colindex", "aria-colspan", "aria-controls", "aria-current", "aria-describedby", "aria-details", "aria-disabled", "aria-dropeffect", "aria-errormessage", "aria-expanded", "aria-flowto", "aria-grabbed", "aria-haspopup", "aria-hidden", "aria-invalid", "aria-keyshortcuts", "aria-label", "aria-labelledby", "aria-level", "aria-live", "aria-modal", "aria-multiline", "aria-multiselectable", "aria-orientation", "aria-owns", "aria-placeholder", "aria-posinset", "aria-pressed", "aria-readonly", "aria-relevant", "aria-required", "aria-roledescription", "aria-rowcount", "aria-rowindex", "aria-rowspan", "aria-selected", "aria-setsize", "aria-sort", "aria-valuemax", "aria-valuemin", "aria-valuenow", "aria-valuetext", "autocapitalize", "class", "colspan", "content", "contenteditable", "datatype", "dir", "draggable", "headers", "hidden", "id", "inlist", "is", "itemid", "itemprop", "itemref", "itemscope", "itemtype", "lang", "ns1:type", "ns2:alphabet", "ns2:ph", "onabort", "onautocomplete", "onautocompleteerror", "onblur", "oncancel", "oncanplay", "oncanplaythrough", "onchange", "onclick", "onclose", "oncontextmenu", "oncuechange", "ondblclick", "ondrag", "ondragend", "ondragenter", "ondragexit", "ondragleave", "ondragover", "ondragstart", "ondrop", "ondurationchange", "onemptied", "onended", "onerror", "onfocus", "onfocusin", "onfocusout", "oninput", "oninvalid", "onkeydown", "onkeypress", "onkeyup", "onload", "onloadeddata", "onloadedmetadata", "onloadstart", "onmousedown", "onmouseenter", "onmouseleave", "onmousemove", "onmouseout", "onmouseover", "onmouseup", "onpause", "onplay", "onplaying", "onprogress", "onratechange", "onreset", "onresize", "onscroll", "onseeked", "onseeking", "onselect", "onsort", "onstalled", "onsubmit", "onsuspend", "ontimeupdate", "ontoggle", "onvolumechange", "onwaiting", "onwheel", "prefix", "property", "rel", "resource", "rev", "role", "rowspan", "slot", "spellcheck", "style", "tabindex", "title", "translate", "typeof", "vocab", "xml:base", "xml:lang" or "xml:space" (with xmlns:ns1="http://www.idpf.org/2007/ops" xmlns:ns2="http://www.w3.org/2001/10/synthesis")
ERROR(RSC-005): .tmp.tmpfjo5g478.epub/EPUB.xhtml.section0024.xhtml(50,20): Error while parsing file: attribute "align" not allowed here; expected attribute "about", "accesskey", "aria-activedescendant", "aria-atomic", "aria-autocomplete", "aria-busy", "aria-checked", "aria-colcount", "aria-colindex", "aria-colspan", "aria-controls", "aria-current", "aria-describedby", "aria-details", "aria-disabled", "aria-dropeffect", "aria-errormessage", "aria-expanded", "aria-flowto", "aria-grabbed", "aria-haspopup", "aria-hidden", "aria-invalid", "aria-keyshortcuts", "aria-label", "aria-labelledby", "aria-level", "aria-live", "aria-modal", "aria-multiline", "aria-multiselectable", "aria-orientation", "aria-owns", "aria-placeholder", "aria-posinset", "aria-pressed", "aria-readonly", "aria-relevant", "aria-required", "aria-roledescription", "aria-rowcount", "aria-rowindex", "aria-rowspan", "aria-selected", "aria-setsize", "aria-sort", "aria-valuemax", "aria-valuemin", "aria-valuenow", "aria-valuetext", "autocapitalize", "class", "colspan", "content", "contenteditable", "datatype", "dir", "draggable", "headers", "hidden", "id", "inlist", "is", "itemid", "itemprop", "itemref", "itemscope", "itemtype", "lang", "ns1:type", "ns2:alphabet", "ns2:ph", "onabort", "onautocomplete", "onautocompleteerror", "onblur", "oncancel", "oncanplay", "oncanplaythrough", "onchange", "onclick", "onclose", "oncontextmenu", "oncuechange", "ondblclick", "ondrag", "ondragend", "ondragenter", "ondragexit", "ondragleave", "ondragover", "ondragstart", "ondrop", "ondurationchange", "onemptied", "onended", "onerror", "onfocus", "onfocusin", "onfocusout", "oninput", "oninvalid", "onkeydown", "onkeypress", "onkeyup", "onload", "onloadeddata", "onloadedmetadata", "onloadstart", "onmousedown", "onmouseenter", "onmouseleave", "onmousemove", "onmouseout", "onmouseover", "onmouseup", "onpause", "onplay", "onplaying", "onprogress", "onratechange", "onreset", "onresize", "onscroll", "onseeked", "onseeking", "onselect", "onsort", "onstalled", "onsubmit", "onsuspend", "ontimeupdate", "ontoggle", "onvolumechange", "onwaiting", "onwheel", "prefix", "property", "rel", "resource", "rev", "role", "rowspan", "slot", "spellcheck", "style", "tabindex", "title", "translate", "typeof", "vocab", "xml:base", "xml:lang" or "xml:space" (with xmlns:ns1="http://www.idpf.org/2007/ops" xmlns:ns2="http://www.w3.org/2001/10/synthesis")
ERROR(RSC-005): .tmp.tmpfjo5g478.epub/EPUB.xhtml.section0024.xhtml(51,20): Error while parsing file: attribute "align" not allowed here; expected attribute "about", "accesskey", "aria-activedescendant", "aria-atomic", "aria-autocomplete", "aria-busy", "aria-checked", "aria-colcount", "aria-colindex", "aria-colspan", "aria-controls", "aria-current", "aria-describedby", "aria-details", "aria-disabled", "aria-dropeffect", "aria-errormessage", "aria-expanded", "aria-flowto", "aria-grabbed", "aria-haspopup", "aria-hidden", "aria-invalid", "aria-keyshortcuts", "aria-label", "aria-labelledby", "aria-level", "aria-live", "aria-modal", "aria-multiline", "aria-multiselectable", "aria-orientation", "aria-owns", "aria-placeholder", "aria-posinset", "aria-pressed", "aria-readonly", "aria-relevant", "aria-required", "aria-roledescription", "aria-rowcount", "aria-rowindex", "aria-rowspan", "aria-selected", "aria-setsize", "aria-sort", "aria-valuemax", "aria-valuemin", "aria-valuenow", "aria-valuetext", "autocapitalize", "class", "colspan", "content", "contenteditable", "datatype", "dir", "draggable", "headers", "hidden", "id", "inlist", "is", "itemid", "itemprop", "itemref", "itemscope", "itemtype", "lang", "ns1:type", "ns2:alphabet", "ns2:ph", "onabort", "onautocomplete", "onautocompleteerror", "onblur", "oncancel", "oncanplay", "oncanplaythrough", "onchange", "onclick", "onclose", "oncontextmenu", "oncuechange", "ondblclick", "ondrag", "ondragend", "ondragenter", "ondragexit", "ondragleave", "ondragover", "ondragstart", "ondrop", "ondurationchange", "onemptied", "onended", "onerror", "onfocus", "onfocusin", "onfocusout", "oninput", "oninvalid", "onkeydown", "onkeypress", "onkeyup", "onload", "onloadeddata", "onloadedmetadata", "onloadstart", "onmousedown", "onmouseenter", "onmouseleave", "onmousemove", "onmouseout", "onmouseover", "onmouseup", "onpause", "onplay", "onplaying", "onprogress", "onratechange", "onreset", "onresize", "onscroll", "onseeked", "onseeking", "onselect", "onsort", "onstalled", "onsubmit", "onsuspend", "ontimeupdate", "ontoggle", "onvolumechange", "onwaiting", "onwheel", "prefix", "property", "rel", "resource", "rev", "role", "rowspan", "slot", "spellcheck", "style", "tabindex", "title", "translate", "typeof", "vocab", "xml:base", "xml:lang" or "xml:space" (with xmlns:ns1="http://www.idpf.org/2007/ops" xmlns:ns2="http://www.w3.org/2001/10/synthesis")
[...]