What does it mean when a Mazda Protege's CD player reads TR when a disc is inserted and then spits it out also how can i fix it?

When a Mazda Protege's CD player displays "TR" upon inserting a disc and then ejects it, it typically indicates a "tray" error, meaning the unit is unable to read the disc properly, possibly due to a dirty lens, a damaged disc, or a malfunctioning mechanism. To fix this, first, try cleaning the CD and the player’s lens with a CD cleaning kit. If the problem persists, check for any visible damage to the disc or consider replacing the CD player if it's malfunctioning.