I'm having the same problem.   Any resolution?

I'm running 64-bit Windows 8.1.   Printer is connected to my Ethernet router, so I'm printing across the local network, not directly by USB. 

Printing from MS Word 2013, the printer works fine with default paper size, but if I change the paper size to something smaller, like envelopes or postcards, I get the PCL6 ERROR - undefined XL code just as described above.

Drivers for 64-bit Windows 8.1 loaded were from downloaded from the Dell Support web site at: http://www.dell.com/support/home/us/en/04/Drivers/DriversDetails?driverId=PKHWK&fileId=3290118292&osCode=WB64A&productCode=dell-2335dn&languageCode=EN&categoryId=DD, Network installation ran, but gave an error message saying "Windows can't install the Dell 2335dn MFP kernel-mode print driver.  To obtain a driver that is compatible with the version of Windows you are running, contact the manufacturer."

Are the drivers posted on the Dell Support site for 64-bit Windows 8.1

Printer firmware is Dell2335dn_A12_v2.70.06.23.

Did you ever find a resolution to this issue?

Three years after the initial post, and I am experiencing the same thing.

Meeee... too..... -_-