On the Files panel of the Preference Settings dialog, you set options relating to file handling. You can choose the program used for archiving and control the options for log file maintenance. And the Auto Backup function lets you save your work automatically at defined intervals.
Auto Backup creates auto backup files based on a time interval. The name of an auto backup file is autobackupNN.max, where autobackup is the main part of the name (autobackup is the default), and NN is an integer from 1 to 99.
For example, if you've set Auto Backup to create three auto backup files at one-minute intervals, Auto Backup will create autobackup1.max, and then a minute later autobackup2.max, and then autobackup3.max. At the fourth minute, the system overwrites autobackup1.max, and so on.
The type of errors covered by these four categories include maps that can't be found, missing UV coordinates, missing output directories, full disks, missing DLLs, disks to which you don't have access, invalid meshes, and obsolete MAX files