I have resolved the issue of not being able to sort a report by the column headings. This also resolved the error I was getting on all Web Pages about the "array" object.
In the website folder the sorttable.js file needs to be edited replacing every occurrence of the ".forEach" with something like ".STforEach".
Here is a link explaining the problem and the resolution.
http://www.kryogenix.org/bugs/sorttable/foreach-collide.html