saiyadjin m you can always open a capx with an older build if you fiddle with the caproj file. To do that you need to:
1) unrar a capx file to its components (each capx is actually a zipped project folder structure).
2) Open the caproj file with a text editor
3) Find the <saved-with-version>19800</saved-with-version> field and change the 5 digit number accordingly (for version r195 type 19500)
4) save the caproj and run it. It should open just fine, unless some feature that was introduced on a later version is being used.