Sorry, my fault .. if the template you're using does not normally have the [SUMMARY] tag, and you add it, you must ALSO add the <SUMMARY> node to the corresponding .xml file.

So, if you've added a [SUMMARY] tag to the template.html file in the default template, make sure to add

 < Object >
  < Token >[SUMMARY]< / Token >
 < / Object >

to the template.xml file as well.

just make sure that in whatever template you are using that for every TAG in the .html file you have a corresponding node in the .xml file. Unfortunately, there's a bug in the Repository that when it's rendering a tag, it looks to the .xml file for the matching setting object, and if the object doesn't exist it throws an error that is caught by the renderer which results in the whole rendering process to stop at that point