The waste toner container is full or installed incorrectly. replace or reseat the waste toner container.

   Turn the machine off, then wait a few minutes for the machine to cool.

   Open the side cover.

   Open the front cover.

   Pull the waste toner container out of the machine using its handle.

   Remove the container's cap from the container as shown below, and use it to close the waste toner container openings.

   Take a new waste toner container out of its package.

   Insert the new container into position and then push it to make sure that it is firmly seated in place.

   Close the front cover firmly. Turn the machine on.