Trying to open CS5 in InDesign CS4

I am working with another graphic designer and she saved her InDesign CS5 file as a InDesign CS4. When I tried to open it in my Academic version of InDesign CS4 version 6.0 I received the following error screen -
Any suggestions - How do I update plugins or tell whether they need updated?
When moving files from CS5 to CS4 - do you have any tips?


CS5 file must be exported to IDML which you can then open in CS4.
Don't expect the document to look the same as it does in CS5. Text will reflow and any new features will be lost or badly mangled.
In short, if you have to work with someone on CS5 you should upgrade.