PDF Troubleshooting

Key Points to Consider

Troubleshooting a PDF file in Adobe Acrobat for Accessibility issues can be quite fiddly. The solutions are not always obvious even with the help information provided. Other times errors are showing up in other PDF checkers but not in Acrobat.

Below lists some of the common issues that can persist in a file and solutions to try.

Can't select text

Try one of the following techniques:

  • Select a smaller area and add to it in stages
  • Select a wider area and convert it to text, then select a smaller area to change eg headings
  • Double click on text

Text boxes keep merging

  • Convert part of text area to a different format such as a heading or figure and then adjust sequence in Order tab.
  • Revert content back to text.

No alternate text for Figure

Often relates to white space, overlays and hidden characters used for page layout.

The affected area is usually highlighted when selected from the Accessibility Report.

  • Use the TouchUp Reading Order tool to set problem content to 'Background'.
  • Check for empty 'Path' type objects in the Reading Order pane. Delete or set to background.

No alternate text for Figure when there is no figure in document

  • Access the Tags Pane on the left of the Acrobat Screen
  • Open out the various page elements to their lowest level
  • Find and delete empty 'Figure' containers

The example below shows a sample section of the Tags pane with an empty <Figure> element highlighted. Delete these to clear the error from the Full Accessibility Check.Empty Figure elements appearing in the Tag pane

If Acrobat is not indicating the relevant page, you have a long document, or cannot find any <Figure> elements try exporting the file to .xml format and use a text editor to search the file.

STILL no alternate text when everything is tagged

Occasionally when you run a final accessibility check you will still receive errors for images with no alternate text.

  • Check the Reading Order pane for figures with no alternate text
  • Check the Tagging pane for empty figure tags (as explained above)
  • Check the Content pane (View > Tools > Content) for figure tags

The example below shows a sample listing from the Content Pane. There are a series of image XObjects (images) that are not contained within a tag.Untagged image objects in the Content Pane

These items need to be marked as 'Artefacts'.

  • Right click on the image object in the Content Pane
  • Select 'Create Artefact' from the menu
  • Choose a suitable artifact type
  • The image object will then be included in an <Artifact> container in the listing

Inaccessible Page Content

First check the Reading Order and Tagging Panes first to see if there are any missed page components or content. Access the Content Pane and look for items that are not within a 'Container' tag. The example below shows a text item (the letter 'y') that is not within a container.

Sample of the Content Pane showing an example of inaccessible untagged content

In the example the inaccessible content belongs in the tag above it. Open both items to access the content within and move the text to its correct location.

Inaccessible Link

  • Access the Content Pane and either select 'Find' from the Options menu available at the top of the listing, or right-click on an item in the pane (eg the top level) and choose 'Find' from the popup menu.
  • In the 'Find Elements' dialogue, change the selection to find 'Unmarked Links'
  • Choose to search the document and then select 'Find' to begin the search
  • When an item is found, select the 'Tag Element' button
  • In the new dialogue, adjust the Type selection to 'Link' and select 'OK'
  • Continue through the document tagging links as they are found.

Inaccessible Form Fields or Digital Signature

  • Check the Reading order Pane
  • Identify a problem form field and ensure it has a listing on the reading order

Content Disappears When Reordering On A Page

When adjusting content order sometimes page components disappear.

If you are working with a multi-page document is is STRONGLY recommended that you save iterative versions of the file as you progress each page. Having several copies at various stages may save you considerable time and frustration if you are dealing with disappearing content.

Heading Structure Incorrect

Check the Tags Pane. Expand out all the various levels and check the order of the tags used - are they correct? Sometimes there are empty tags in the structure.

Select a heading tag and right click to change its properties to the correct heading level or to a different tag type.

To make it easier working between windows, keep the properties dialogue open as you scale up and down the tree adjusting tags.

Table With No Headings

First check that you haven't missed a table in your content.

Open the Tags Pane and expand out the various levels - there can sometimes be an empty table left in the structure. These can be deleted but make sure you don't accidentally delete page content.

The example below shows a section of the Tags pane with a <Table> element highlighted that has no page content. Delete these to clear the error relating to missing table headings from the Full Accessibility Check.

Empty table appearing in the Tags pane

If Acrobat is not indicating the relevant page, you have a long document or cannot find any Table elements try exporting the file to .xml format and use a text editor to search the file.