My dvd player showing error message?

Hi can anyone help, i have a dvd player that keeps showing error message ' wrong disk' each time a put a disk in. i have bought another player but would love to see if this one can be fixed so i could use it up stairs before i throw it out. The make is Acousitic Solutions model: DVD-204. If anyone has an solution please let me know ASAP.
thanks you and have a Very Merry Christmas.