Whenever my Macintosh attempts to print to my LaserWriter it displays this error:

"Document (name of print job) failed to print on the printer (printer name) because of an error -8940. Cancel Job, Hold Job and Try Again"

A similar message may appear when I attempt to Auto Setup the DTP with the Desktop Printer Utility or when using the Finder's Printing menu.

What does this mean and how do I fix it?

Error -8940 is an errInvalidDTPType, returned from psGetDTPType. This error code indicates that the PAPA Resource described an invalid or unrecognized desktop printer type. Basically your desktop printer has incorrect information about your printer and as a result is unable to communicate with and print to it properly.

Typically this occurs when creating a desktop printer whereas the error message is typically displayed when attempting to communicate and open up a PAP connection with the printer. Clues that a desktop printer may not work include:

1. It has a generic icon.

2. The Info window for the desktop printer may have no information listed in the Zone field. (Choose Get Info from the File menu to open the Desktop Printer's Info window.)

• Note that an asterisk is an acceptable Zone name. A blank Zone field indicates a problem with the desktop printer, when using LaserWriter software 8.5.1 or later.
• Desktop printers created with older drivers or for IP or other connections may not list a Zone or include a Zone field at all.

Often this issue is easily worked around by throwing away the existing desktop printer icon, emptying the Trash, then creating a new one with the Chooser, Desktop Printer Utility, or the Mac OS Setup Assistant. However, there are some configurations where this will not work as expected, described in more detail below.

Using the Desktop Printer Utility v1.0, 1.1, or 1.2, On a Network That Has No Zone

You will likely encounter an -8940 error message when creating or when printing to an AppleTalk desktop printer created with the Desktop Printer Utility on a network that has no defined zone or zones. The error message will also occur when you create an AppleTalk desktop printer using the DTP Utility, when the printer is directly connected to your Macintosh with a serial cable.

The workaround is to use the Chooser or Mac OS Set Up Assistant to create and configure your AppleTalk desktop printer. You may continue to use the Desktop Printer Utility to configure an IP, USB or other type of PostScript laser printer desktop printer.

Using the Chooser on a Macintosh Connected to LocalTalk, When a Bridge is Present

You will likely encounter an -8940 error message when creating or when printing to a desktop printer created with the Chooser, if the client and printer are both on the same LocalTalk segment, and there is a LocalTalk Bridge or possibly a hardware bridge on that segment. Note that this should not pose difficulties if the Macintosh is on Ethernet and the printer is on LocalTalk, or vice versa.

The workaround is to use the Mac OS Setup Assistant to select the printer. Alternatively, disable the bridge, choose and create the Desktop Printer, then re-enable the bridge. A third option is to install LaserWriter 8 and PrintingLib versions 8.4.3 and print from them. Note that LaserWriter 8, version 8.4.3 has received very little testing after Mac OS 8.0, so its compatibility with current Mac OS system software is unknown.

Described above are two very specific situations where the desktop printer created for your printer may not be able to communicate with the printer and returns an -8940 error. This occurs at the time the desktop printer is created, but may be discovered later when the desktop printer attempts to open up an AppleTalk connection and communicate with the printer.

If you encounter an -8940 error, check whether your environment is described as above. If so, you may wish to pursue one of the suggested workarounds.

If your printing environment is not as described above, the first workaround is to throw away the desktop printer icon for the printer you are unable to print to, empty the Trash, then attempt to create a new DTP.

In some cases you may need to throw away the old DTP and the Parsed PPD Folder (System Folder: Preferences: Printing Prefs: Parsed PPD Folder), empty the Trash, then rebuild the Desktop Printers DB. To rebuild the Desktop Printers DB:

1. Restart your Macintosh.

2. Press and hold down the Command and Option keys until this message is displayed: Are you sure you want to rebuild the desktop file on the disk "your hard disk"?

3. Click OK to rebuild the desktop files.

If difficulties were first encountered after installing other vendors' PostScript printer software, consider removing or throwing away that printer software, then reinstall the latest version of LaserWriter 8 from CD or from Apple Software Updates. The LaserWriter 8 driver uses PostScript Printer Description (PPD) files to determine the characteristics of the printers it uses. PPDs for most popular printers may be downloaded from http://www.ppds.com/ or obtained from your printers' manufacturer. Copy the PPD to the Printer Descriptions folder (System Folder: Extensions folder: Printer Description).

If -8940 errors persist, be very observant when creating a new desktop printer. For example, if you use the Chooser to create a desktop printer, and the printer is not visible in the Chooser at all or if the Auto Selection process does not work as anticipated, some other issue may exist that could result in the desktop printer not being created. Such a situation preventing the proper creation of the desktop printer may require additional troubleshooting to identify and work around.