I saved the capx from the forum (someone's dropbox) directly to my dropbox.
Opening it from dropbox in C3 (today) is not working.
Did I do something incorrectly?
Trying to understand the editing and saving aspect of your OP.
You say you originally opened/imported a .capx into C3, editied it, then saved it to dropbox on a different computer(?). If you saved from C3 then it wouldn't be a .capx.
Do you see my confusion? (maybe I'm having a bad Sunday!).