Missing required parameter from for event open

I have a MAC OS X Snow leopard on which I have Adobe InDesign installed on. Whenever I try to open any file, I get an error message.
Missing required parameter from for event open
I click on OK and then try but again it comes back with the same error. It does not show me which parameter is missing. All the other files do not have any issues. Is this because I upgraded recently to OS 10.6?
Does anyone else have the same issue?
