I didn't do anything special. No Mac OS update nor did I update the application. I use the application every day and found it completely empty when I opened it this morning.
Take note of your library location (Preferences > Sync > Library Location).
Close Quiver. Delete the cache file and the search index file:
~/Library/Containers/com.happenapps.Quiver/Data/Library/Application\ Support/Quiver/cache.db
~/Library/Containers/com.happenapps.Quiver/Data/Library/Application\ Support/Quiver/index-v2.dat
Double click on your library to open Quiver again.
I didn't do anything special. No Mac OS update nor did I update the application. I use the application every day and found it completely empty when I opened it this morning.
Mac OS: 10.14.3 Quiver: 2.3.4