title_body: I have two error messages that are affecting many of my ePub 3 files I am stumped! I have two validation errors left to correct. Unfortunately, they impact many pages.
  
  1.ERROR: epub9.epub/OEBPS/j83643-Flower-Fairy_-epubBody-1.xhtml(26,162): ‘OEBPS/image/illus010b_clip_blurb.png': referenced resource is not declared in the OPF manifest.
  
  It is in the manifest under images. It is also listed in the images in the image folder. I checked j83643-Flower-Fairy_-epubBody-1.xhtml and it is in there as well. So What do I do next. This error message is given for most of the images. The scanned images with long names are ok.
  I see no difference in their context.
  
  
  Then the error message changes for the same images: WARNING: epub9.epub: items (OEBPS/image/illus010b_clip_blurb.jpg) exists in the zip file, but is not declared in the OPF file. 
  
  
  I don’t know why the semantics changed. It also gives this error for some of the audio and smil files.
  
  If I could fix one example for each type of error, I could fix them all. I have checked the image, audio, smil, and xhtml files. They are listed in all of them and in the content opf.
  
  Hope someone out there can help me,
  Janis
upvoted_answer: The first error message is telling you that the file referenced is not declared in the &lt;manifest&gt; section of the content.opf file. The second one is telling you that the file exists in your epub, but is not declared in the &lt;manifest&gt; section of your content.opf file. The important thing to note is that in the error messages you listed, there are two different files being talked about:
  
  
  image/illus010b_clip_blurb.png
  image/illus010b_clip_blurb.jpg
  
  
  See the two different file extensions? That's probably part of the problem. The file j83643-Flower-Fairy_-epubBody-1.xhtml is looking for a png file and not finding one. Meanwhile, there's a jpg file of that name that isn't declared in your &lt;manifest&gt;.
  
  The first thing to do is to open up the content.opf file and check to see what it's expecting to be in there. If the png is listed in the &lt;manifest&gt;, simply converting the image from a jpg to a png should make your error go away, as the xhtml file would be able to find the file it's looking for, and the content.opf file would no longer be finding an unexpected jpg file.
  
  If the png is not listed, you'll have to either add an entry for it and convert the image to a png, or add an entry for the jpg and change the &lt;img&gt; in the xhtml file to refer to the jpg file.
  
  If your file paths and names are all correct and the file is in the &lt;manifest&gt;, I'd suggest checking the encoding on the content.opf file to be sure that it's utf-8, as using ANSI encoding can cause some weird errors sometimes.