What is Fatal Error 112?
The second paper trays for C7200/C7400 printers are not compatible with C7100/C7300/C7500 printers (and vice versa).
Also, the second paper trays for C9200/C9400 printers are not compatible with C9300/C9500 printers (and vice versa).
Fitting the wrong type of paper tray to a printer may be physically possible, however, the printer will then display fatal error 112 on the operation panel.
If your printer displays fatal error 112 on the operation panel then please check whether the correct 2nd tray is fitted to the relevant printer model. The order number and related details for 2nd Paper Trays can be found on this web site.
The following pictures are 2nd Paper Trays for C7000 and C9000 Series printers respectively.