This fix assumes you have set up an LPR printer before. If you have not, use the Desktop Printer Utility to add an LPR printer. It is located in the Utilities folder inside the "Applications (Mac OS 9)" folder.
Steps to select an LPR printer in Classic:
1. From a Classic application, choose Chooser from the Apple menu.
2. Click the LaserWriter icon. A list of AppleTalk devices appears, which you should ignore.
3. Close the Chooser. When you print from Classic, you are now able to choose the LPR based printer in the print dialog.
Tip: If the job doesn't print as expected, try printing it in the foreground. Choose Background Printing from the Print window's preferences pop-up menu, then select Print In: Foreground.