Fix Print Error: undefinedresult Offending Command: xshow
How to fix it in 6 steps:
1. From the Finder, select Go > Go to Folder...
2. In the dialog box, enter: /etc/cups/ppd
3. In the folder that opens, you should see a .ppd file with the name of your printer -- open it in TextEdit (you can do this by dragging the file onto the TextEdit app)
4. Look for the line *TTRasterizer: Type42
5. Change "Type42" to "None"
6. Then Save (you may need to enter an Admin password)