{"p":"can-20","op":"mint","tick":"can","amt":"1000","rows":[{"df":"qa","content":[{"q":"How to recover when a blockchain upgrade fails?","a":"Backup data: After understanding the cause of the failure, backup  the blockchain data immediately to prevent data loss. Backup methods can include offline backup, cloud backup, etc."}]}],"pr":"24d2844dba4f8eae61f017e04d0977ad1b123673312c301dba199b4f52ca1819"}