In the AppleScanner software, the brightness and contrast settings can be saved. Each setting that is saved has to be named; the default name is "Untitled Settings".
If the settings are saved as "Untitled Settings", the next default name is "Untitled Settings 2". The problem occurs when saving these new settings as "Untitled Settings 2": when an image is scanned and saved, a System Error ID 12 occurs.
The reason for the error is that maximum length for a setting name is 16 characters, and "Untitled Settings 2" violates this rule.
To work around this problem, each time a new setting is saved, use the "Save as..." option, and give the file a name of 16 or fewer characters.