I refer to a similar forum post here - http://forums.adobe.com/message/4081971 - which outlines a similar problem with opening a file.
The difference is the file I can no longer open was created using Adobe indd CS5.5 and I am opening it with Adobe indd CS5.5. I have never had this issue previously. The only change is to a new OS on Mac - Version 10.8.2. Error message says "Cannot open "File name" please upgrade your plugins to the latest version or update to the latest version of Adobe" - I know there is CS6 but why should I now need to upgrade suddenly?
Can anyone help here? I can forward a link to the file in question if needs be.
@Catie – did you verify, if your InDesign file is saved in version CS5.5?
Here is the full story of "IDentify.jsx":[Ann] Identify Your InDesign File
If the problem is due to a corruption of plug-in version information, I fear you have no chance other than:
1. Update CS5.5 to the latest bug-fix version => 7.5.3
2. Download a trial version of InDesign CS6, open and export the file to IDML and re-open it in InDesign CS5.5 (though this might not work for a corrupted file)
3. Try to open the file on a different machine
Are there 3rd party plug-ins involved? If so contact their makers…