Update: kuddos to Groundspeak, they reversed the change that broke the import. Should be working fine again.
Unfortunately something seems to be changed on Groundspeaks side of the API. Now most API imports make iCaching crash.
I was notified about this by several users (thanks for that!). I’ve made a hot fix and will submit that as soon as possible to the App Store.
For now, the only workaround is to import old-fashioned GPX files.