Ebook images not exporting in free version of PB

[zwhnz]

Prerequisites

• [x] Can you reproduce the behavior you wish to address with all other plugins deactivated?
• [x] Are you running the latest version of Pressbooks and the latest version of WordPress?
• [x] Are you experiencing this issue with one of our built-in root or book themes?
• [x] Did you perform a cursory search to see if your bug or enhancement is already listed?

  Description

• 4-5 users reported images failing to export in their epub and mobi files
• all are on the free version of PB, but all using under the 5MB of storage
• image links have been checked and are accurate/internal to books
• disabling storage quota has no effect
• upgrading to paid version fixes issue (but not all want to and shouldn't have to)
• images display correctly in web and PDF outputs
• replicated issue in test book when upgrade is removed
• error message from validator: Remote resource reference not allowed; resource must be placed in the OCF
• checked files in Calibre - image definitely not present

Can send URLs/files/error reports as you need - let me know in Slack.

Steps to Reproduce

1. Go to a free book (not upgraded) with images
2. Export as epub and mobi with usual method (error message will appear)
3. Open in Adobe Digital Editions/Kindle Previewer as appropriate
4. Check images
5. Check error logs

Expected behavior: [What you expected to happen]

File exports with no errors, images show when opening files in ADE and Kindle Previewer

Actual behavior: [What actually happened]

Error messages appears on export screen: Warning: The export has validation errors. See logs for more details.

Error email states: remote resource reference not allowed; resource must be placed in the OCF

When previewing files: Images are either absent, or show an error (camera/exclamation mark) depending on previewer

Themes

Root Theme: Pressbooks Book Theme: Various - Bradbury, Austen Two, Leonard, Custom CSS

Versions

My versions: (unknown for users) Pressbooks: 3.6.0 WordPress: 4.5.3 PHP: 5.6

You can get the version of Pressbooks from the readme.txt file in the Pressbooks plugin (usually located at http://<yourdomain.tld>/wp-content/plugins/pressbooks/readme.txt) and the version of WordPress from the readme.html file in the WordPress root directory (usually located at http://<yourdomain.tld>/readme.html). You can usually get your PHP version from your web host, or by using the phpversion() function.

[hussnainsheikh]

Hi,

I am still facing the exact issue in Pressbook v5.9.0 while exporting to EPUB3. I am wondering if this issue if fixed back in 2016 then why I am facing it. Any thought? Thank you!