I'm running Echo Workstation 8206 on an XP Pro SP2 box. I have a differential image run overnight. Sometimes it runs fine, other times it hangs up, waiting for an answer to this message. I know that inability to see the target drive is one reason for the error below, but are there any others? This is a differential image, so if it can't see a full backup, it should make a new one. I would hope that if the full backup it sees is corrupted, it would also make a new full one. "Last volume of a multi-volume archive" does not apply to differential. What else could produce this message and make the program wait for an operator to key yes or no"? Even in quiet mode it hangs up. is waiting for user interaction. Description: Create Differential Backup Archive From: Disk 1 To file: "J:\Diff.tib" Password protected Compression: Normal Problem Info: Incremental backup is not possible. Problem Details: The file you have chosen is not the Acronis True Image backup, or the file is corrupted, or this is not the last volume of multi-volume archive. Do you wish to proceed with the current file name? If you proceed, the chosen file will be overwritten and the full backup will be created. Otherwise, you will create an incremental backup by choosing the valid archive file name or the last volume of multi-volume archive.