Whereas lulu.com is being preferred by self-published authors of ebooks, it may put them in trouble as well especially when they submit an epub file, which is not formatted as per the epub publishing guidelines of lulu.com. And, such epubs often results in the ERROR: IOException: Unresolved external XML entity: ‘http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd’ in OEBPS/Text/Section0002.xhtml
Note: Section0002.xhtml is the name of one of the html files in the epub file, which is uploaded to lulu.com, but could not pass lulu.com’s epub validation. In your epub file, this can be different so do not confuse you with the file name.
When you upload file on lulu.com and its validation is failed, then you get a message stating that validation is failed. And, lulu.com also provides you with a .txt file containing reasons due to which validation is failed, and you should fix those errors before resubmitting epub on lulu.com for publishing. However, that .txt file is intended for advanced users who understand html, xhtml, xml, and other such techniques. Hence, if you are not an advanced user then you might not be able to fix issues.
Resolving ERROR: IOException: Unresolved external XML entity
The only solution to resolve the ERROR: IOException: Unresolved external XML entity: ‘http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd‘ in OEBPS/Text/Section0002.xhtml is open the source files and format it as per the guidelines of lulu.com after understanding the reasons given the .txt file provided by lulu.com.
If you have created the epub file from Word Doc or PDF using a free converter then you need to first format that Word Doc or PDF as per the lulu.com’s guidelines and then do the conversion again. Or, if you have hired someone to create epub for you then contact that person or company to fix all the issues.
However, in case, you do not see any relief from anywhere, we are always here to assist you. We have good understanding of lulu.com’s guidelines,html, xhtml, xml, and css; therefore, we can perfectly resolve the ERROR: IOException: Unresolved external XML entity: ‘http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd’ in OEBPS/Text/Section0002.xhtml
We have expertise (with advanced knowledge in html, xhtml, xml, and css) who can better understand the reasons behind the validation failure and hence, can resolve them. Contact us at firstname.lastname@example.org or visit the contact page to fill the form. We shall resolve the issue within 24 to 48 hours for a minimum cost. Contact us now to know the cost and for a solution.