the error message is"wrong application level"...
what does it mean??
My first suggestion is to look at the Release of the Files you are trying to open, do you have a copy of the error ? I know alot of designers are running a later release, Like R21. Keep in mind Catia is NOT upward Compatible...So if the file was created with R21, you wont be able to open it with R16
What is the error you get when you try to load them ? The only way I know is by the error message you get
OK...Yes, that is the problem...you have an older version of catia than the part was created with