Steps:

1.Select [Root object] – [Workspace Settings] from the object window.
2.Select the “Settings” tab in the properties window.
3.Specify the maximum number of backup files for the “Max number of Ar3/Ar4 backup files” property.

窶ｻIf the number of existing files exceeds the specified maximum number, the existing files will be forcibly deleted from the oldest ones first.