This issue causes many errors to show up in a pdf accessibility check and is caused from an option not being checked in the print/export settings of the source document. These instructions assume the source document is a Microsoft Document, in which case most, if not all, the export options will be the same.
Although there is more than one option to create a pdf, this one seems to be the most common to ensure the least amount of accessibility issues in the pdf. However, you may want to test other on your own to see if they fit your needs better. Each one of them should have some sort of configuration options and should have the one described below.
- Ensure your source document is opened.
- Select "File" > "Export". You will be presented with the following options.
- Choose "Create PDF/XPS Document".
- Click the "Create PDF/XPS" button. You will be presented with a popup to select where you want the file saved.
- In this popup, choose the "Options" button. Another popup will be displayed with some configuration settings.
- Find "Document structure tags for accessibility" checkbox and ensure it is CHECKED.
- Click "OK".
- Make sure you name the file properly you want to save.
- Click "Publish" and your file will be saved.
- Open this file with acrobat and re-run the acceesibility checker to ensure the errors have diminished, if not gone away completely.