I went to file associations there was no .xml
format, when I added it, all editors were added automatically and they are static writing me something like:
Click default on *.xml and Text editor
Close all files and then try to open an XML file again.
For people who are looking for a simple text based XML editor, the default XML editor in Eclipse comes with a text based view with syntax highlighting (as it should). It's just not intuitive to know this view exists.
By default the view is "Design". "Source" is the simple text based view with syntax highlighting.
For a much better illustration, see:
How do I view xml in Eclipse with simple syntax highlighting?
My problem was that I opened the pom.xml with the maven editor - I wanted it to be opened with the maven editor but to open in the "source" view - achieved it by:
Typing xml in the search box did not include this page in the results.