Cd player reads err on display

It sounds as if the player laser is dirty. Vacuum all around the insert slot and then take some canned air and blast some air in there being careful not to inject any liquid propellant while doing so.
Try that first, and test. If that doesn't help, get a cleaning CD and follow the manufacturer's directions.
If that still doesn't help, you've got yourself a failed disc reader and you'll need to replace it. Good luck!

Error 1"The changer is unable to load or unload a disc, the changer can't operate".

Means your machine is in need of repair (unable to load or unload a disc), remove the cd player and send it to the manufacturer for repair (that's what the car dealer will do if you ask them to repair it for you).

with the 6 disc cd single slot you have to select load then the number of the empty slot, then wait for the motors in the player to stop and insert disc

The following is the owner's manual for your 2004 Dodge Neon:

http://www.dodge.com/en/owners/manuals/index.html?year=2004&nameplate=Neon

P.99 describes how to load discs:

1. Select and press any numbered button without an illuminated light above it.
2. Insert the CD while the light above the chosen button is flashing and the two lights on either side of the slot are illuminated.
3. Upon insertion, the CD will begin to play, and both the button light and the lights in the corner of the loading slot will illuminate.
4. Repeat the process for loading any additional CDs. The CD playe rwill stop while additional CDs are loaded.

Playing Discs
The radio will show the CD number, the CD track number, and the Track Time Elapsed while the radio is in the CD mode. IF more than one CD is loaded in the changer, the changer will automatically play the next disc after playing the last track of the current disc.

Wow, that's a lot of typing.
I didn't know the 2004 Dodge Neon had such a nice changer.
Good luck.

Hi:
Unfortunately, the ERR is a disk read error, and usually caused by the laser being out of alignment. It seems in my experience that An aftermarket deck is a cheaper solution than having it repaired.

CD player is not working. Motor will not unload or load discs. It will play CDs fine but cannot change them. Unit will need to be repaired by an audio specialoist or replaced.

its a very common problem with g35 in dash clarion cd changer head units. a small plastic gear gets worn or brakes and wont eject or change cds. you need a new one, should be covered under your warranty.

and to get your cds out try this.

This is not a fuse problem, it may be a dirty laser lens or a broken loading mechanism, buy a CD player cleaner disk, if that won't work you will have to pull the unit out and send it in for repair at an authorized GM electronics repair station.

It happens to me all the time on my 2002. Try cycling the load and unload buttons for the stuck CD location. If that doesn't work try ejecting the CD. When the slot door opens, try putting another CD into the slot and push on the edge of the stuck CD.