Not sure if it’s related but I just updated to v4.19.2 and I just noticed all my assets and purchased content is gone. It just says"your vault is empty".
I was able to find the VaultCache under program files/ epic game/ launcher/ VaultCache but I don’t know a way to get it back under my projects.
Same symptom here: “Your vault is empty”, although hovering the little cloud icon just above that showed “total size of locally cached content” was over 40gb.
In my case, I simply exited and restarted the Epic Launcher, and my vault repopulated as normal.
Just a thought. This sometimes happens to me when I’ve typed something into the Search field.
Make sure you don’t type anything in there.