Fixing “There is an xml error in the body." errors with Annotum 2.0
“There is an xml error in the body. If this article is in a published state it will be transitioned into a non-published state until these are fixed”.
Invalid XML usually comes from content created prior to version 2, and will need to be fixed in order to publish (or re-publish) your article.
To fix these particular errors, you need to go into the anno-source tool and correct any invalid XML.
Toolbar button:

Screenshot:

One typical error shows up as missing images in the article editor. To fix this open the code editor (click the anno-source button), and find the <media elements that are causing the errors. Then modify the XML as follows:
Before: <media href="blah"
After: <media xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="blah"
(Here, "blah" is the href for your link.).
You may see some other errors when you click "validate"; you'll have to fix them to republish the article - please feel free to submit a support ticket via http://annotum.uservoice.com should you need assistance.
For reference, here is a demo article that contains valid XML:
http://demo.annotum.org/article/quis-nudus-iuvenem-discessum-adulta/
(Here, "blah" is the href for your link.).
You may see some other errors when you click "validate"; you'll have to fix them to republish the article - please feel free to submit a support ticket via http://annotum.uservoice.com should you need assistance.
For reference, here is a demo article that contains valid XML:
http://demo.annotum.org/article/quis-nudus-iuvenem-discessum-adulta/