You don't see the + sign for adding activities?
Garmin again ...not able to provide those files for us costumers. If you want I can provide a Dropbox-folder with all activities. You can copy and paste the one you need in your activity-folder of the watch.
As post above says, use the mobile app GC Mobile to add them back in.
Hello I'm missing a couple of apps. Do you mind sharing the app files please?