I hit an interesting error after updating my nvim plugins today. I'm sti not even quite sure what a ShaDa file is, but I found min in my nvim state directory, unlike this issue that mentions it being in share.
The Error.
Error while reading ShaDa file:
The Fix
mv ~/.local/state/nvim/shada/main.shada ~/.local/state/nvim/shada/main.shada.bak