Versions 30.0 and 30.1 contained a bug in the wallet migration logic that could completely delete your wallet files
RPC command to convert an old BDB wallet to the modern SQLite-based descriptor format. Manual Migration (The "Dump" Method) : For very old files, you can use the dumpwallet command in the Debug Console bitcoin core walletdat upd
Marcus stopped breathing.
The terminal flickered. For one heart-stopping second, the screen went black. Then it returned. Versions 30