The NFT-Devnet Has Been Reset
The "NFT-Devnet" is a test network running experimental code to support Non-Fungible Tokens (NFTs) natively on the XRP Ledger (per the XLS-20 draft standard). Ripple has reset the NFT-Devnet while upgrading it to the latest version of the preview code.
All accounts funded, NFTs minted, and other data in the NFT-Devnet have been discarded as part of the reset. If you use the NFT-Devnet for development, you should use the XRP Faucets to fund new accounts and re-create your settings as necessary.