Can't What displayed error message means

I agree. 49 + 79 are usually a bad file, especially pdfs.

49 error normally means that the information sent to the printer is corrupted clear the print que shut down printer and restart. If problem still there then shutdown the printer then remove one of the additional memory turn back on if still same problem repeat removal of the next memory replacing the one you have just removed and so on. After you have done this and you are still getting the problem then it is 99% certain that the printer system firmware is corrupted or the formatter control board is faulty.

Thanks J