This would best be handled by the person who serviced your unit. If the technician changed something inside of the service menu, you may be receiving this message in error.
Content filter may suggest that either that the TV is set in the wrong region, or that somehow the HDCP (copy protection) mechanism isn't allowing received broadcasts with the digital connection.
I recently had this TV in for repair to replace the power supply. Upon return, when I connect it to my Comcast HD cable box via HDMI, I get an error message: "The HD content filter has been compromised. Please use the Yb Yr Y connection for HD content" or something like that. Does anyone have experience with that? did the power supply repair reset something inside the TV? Please help.