How to install printer Lexmark 4900 series in wifi

Question

E [24/Jun/2013:19:50:37 +0200] _4900_Series_<MAC:0020003e726a>: Les permissions du fichier « /usr/libexec/cups/backend/lexnet3 » ne sont pas sécurisées (0100775/uid=0/gid=80).
E [24/Jun/2013:19:50:37 +0200] [Job 21] Stopping job because the sheduler could not execute the backend.
E [24/Jun/2013:20:01:01 +0200] [CGI] Les permissions du fichier « /usr/libexec/cups/backend/lexnet3 » ne sont pas sécurisées (0100775/uid=0/gid=80).
E [24/Jun/2013:20:38:47 +0200] [Job 27] Unable to read CUPS raster data

Answer 1

Launch the Console application in any of the following ways:
☞ Enter the first few letters of its name into a Spotlight search. Select it in the results (it should be at the top.)
☞ In the Finder, select Go ▹ Utilities from the menu bar, or press the key combination shift-command-U. The application is in the folder that opens.
☞ Open LaunchPad. Click Utilities, then Console in the icon grid.
Select "/var/log/cups/error_log" from the file list on the left side of the Console window. If you don't see that list, select
View ▹ Show Log List
from the menu bar. Then select the messages from the time of the last failed printing attempt. Copy them to the Clipboard (command-C). Paste into a reply to this message (command-V).
If there are runs of repeated messages, post only one example of each. Don’t post many repetitions of the same message.
When posting a log extract, be selective. In most cases, a few dozen lines are more than enough.
Please do not indiscriminately dump thousands of lines from the log into this discussion.