Occasionally it happens that after some sort of hard shutdown (such as powerloss or having to REISUB) KWallet looses it’s entire wallet file. This has happened to me twice so far. The first time major parts of my KDE config was lost, so this appears to be not strictly restrained to KWallet, but I suppose it’s most problematic for KWallet as we’d expect a Password manager to keep the passwords safe and not loose them easily.

I suppose this might happen if the system shuts down while KWallet tries to write to the encrypted wallet.

In any case I think that KWallet should handle it’s Wallet files more carefully, potentially creating backups before writing to the wallet and such.