A S.M.A.R.T. error is a predictive failure notice. The drive will fail in the near future and should be replaced at the next earliest time possible. S.M.A.R.T. (Self-Monitoring, Analysis and Reporting Technology) is a feature that monitors the health and performance of hard drives and alerts the user of any potential problems or failures. S.M.A.R.T. can detect various indicators of drive degradation, such as bad sectors, read/write errors, temperature, or spin-up time. If a S.M.A.R.T. error is reported, it means that the drive has exceeded a predefined threshold of acceptable operation and is likely to fail soon. The drive may still function normally for a while, but it is recommended to back up the data and replace the drive as soon as possible to avoid data loss or system downtime.