Why should I delete the kaspa-mainnet folder before bootstrapping a node snapshot?

Before importing a bootstrap snapshot, delete any existing kaspa-mainnet folder in your destination directory. When kaspad — Kaspa's node software — has been started and stopped more than once, leftover database files from those earlier runs accumulate inside that folder. The kaspad database engine cannot reliably sort out a mixture of old and new files, and that conflict is likely to cause it to crash on startup. Taking a few seconds to remove the old folder before you begin is the simplest way to avoid a confusing crash that has nothing to do with your hardware or network.