If you go to Repository Explorer and right click on the cascading dynamic parameter, there should be an option to change the rights. You will need to permit rights for all users.

Second option (which I had to do) was rebuild the report and remove the faulty parameter.

There is also help on this topic in the business objects forum (sorry, don't have the direct link at the moment). You should be able to do a search in Google or withing Business Objects website on the exact error (removing file names).