HP laserjet M551 gives the following error to 1 windows 7 laptop. PCL XL error, Subsystem: KERNEL, Error: IllegalOperatorSequence, Operator:EndSession, Position 3898, but the position number changes.

PCL XL errors are error messages from the PCL6 interpreter in the printer. It's the printer's way of telling you there is something wrong with the commends it received.

If this happens will all documents, the easiest way to fix it is to use a PCL5 driver. If only one document is affected, try changing something within the document.

Thanks DansDadUK,
I'll try that today.  Thanks for the good explanation of the error message!  
grampadavid

Thanks hdhondt,
I am going to try DansDadsUK trouble shooting  steps first, then if I can't see the error I'll switch back to PCL5 drivers.
It's great to get answers from people that know  what PCL XL errors really are!!!

Again Thanks much!!
Grampadavid

DansDadUK,
Glad to find your explanation of how to troubeshoot those PCL XL errors. We usually just switched to a PCL 5 driver to resolve that type of issue.  I never knew you can analyze the error in that way.
Thanks!
Alicia

Alicia

You can capture a print stream to a file, then analyse its contents using my PRN File Analyse tool (although there are others available from other sources!).
But, whilst it may reveal the underlying problem, this only helps if you have sufficient knowledge of the language to suggest a workaround (if there is one); a 'hard' driver fault usually means waiting (perhaps for ever) on a new driver version.

... and with the current generation of LaserJet printers, the format of the PCL XL error messages appears to have changed; so, for example, instead of:

PCL XL error
 Subsystem: KERNEL
 Error: IllegalAttribute
 Operator:CloseDataSource
 Position 15

Select allOpen in new window

you might get something like:

PCL XL error
 Subsystem: KERNEL
 Error: IllegalAttribute
 File Name: kerlib.c
 Line Number 1381

Select allOpen in new window

which no longer references the erroneous operator, or its position in the stream; the file name and line number are meaningful only to the printer manufacturer (or whoever they sub-contracted the writing of the firmware to).

Of course, changing to use a PCL5 driver (as you and hdhondt have both referred to) means that you will no longer get PCL XL errors.
However, different errors, related to the PCL5 Page Description Language. may occur, although they will not necessarily be detected or reported; for example, the PCL5 interpreter will just ignore invalid escape sequences (provided they have the correct syntax), or just print them as text, but won't halt the print and display an error page, so you won't necessarily be aware that an error has occurred.

Thanks much