Epson AcuLaser C8600 Reference Manual page 320

Check Paper Type
The media loaded in the printer does not match the paper type
setting in the printer driver. Media that matches only the paper
size setting will be used for printing.
To clear this error, select
Reset Menu. See "How to access the control panel menus" on page
167 for instructions.
Check Transparency
You have loaded media other than transparencies when the Paper
Type setting in the printer driver is Transparency. The printer
stops loading to prevent printer damage. Load transparencies in
the specified paper source, then press the Start/Stop button.
Collate was disabled
Printing by specifying the number of copies is no longer possible
due to a lack of memory (RAM) or free disk space on the optional
Hard Disk Drive. If this error occurs, print only one copy at a time.
To clear this error, select
Reset Menu. See "How to access the control panel menus" on page
167 for instructions.
Cover A Open
Cover A, the output path cover on the left side of the printer, is
open. Close the cover and the error is automatically cleared.
Cover D Open
Cover D, the paper cassette cover on the right side of the printer,
is open. Close the cover and the error is automatically cleared.
318 Troubleshooting
from the control panel's
from the control panel's