HP Laserjet 1012 Unsupported Personality: PCL

Hi, Scott -

According to this HP Support webpage that error is usually generated by incorrect drivers having got into the stew. Yes, the info on that page does seem to have to do with PC/Windows machines, but a re-install of the HP software for that printer may be a solution. In particular, I'd delete the PPD for the printer before re-installing the software.

Other possibilities -

Try increasing the Preferred memory allocations for the printware. This can include PrintMonitor and Desktop PrintMonitor, both of which reside in the Extensions folder, and the desktop printer icon itself if Desktop Printing is active.

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Chooser uses the LaserWriter 8 extension as if it were also a preferences file, writing to it fairly often. This means that extension can become corrupted or damaged. When that happens, replacing it is the only solution.

That extension can be copied from another working machine with the same OS version.

Or, you can use the utility TomeViewer to extract (expand) any files you want from an Installation Tome on an OS Install CD or download disk image, without running the installer.
How to use TomeViewer

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Sometimes throwing away any associated preference files will fix a communication/networking/printing issue. In addition to the one named LaserWriter 8 Prefs, try also tossing ASLM Preferences.

Restart after throwing away a preference file.

Hi, Scott -

If the printer is not shared, be sure the control panel "USB Printer Sharing" and the extension "USB Printer Sharing Extension" have been disabled in Extensions Manager.

...this is a USB printer, so it doesn't use Laserwriter 8.

But Chooser may be using it anyway. Check the Date Modified for LaserWriter 8, either via Get Info or by setting the Extensions folder to View as List (if that hasn't already been set that way) - if that date is more recent than it should be if left unused, consider replacing that file.