I am still having the "app crash on startup"
running iOS 10.3.3 on iphone 7
updated the Geocaching app to version 5.6.1
i restarted my phone and it works now. Sorry for the noise.
iOS-
In this release, we squashed a bunch of bugs and made several performance improvements. Most importantly, we fixed a bug that was causing the app to crash on startup for some users immediately after updating to a new version.