Enform "can't read CD" alert

[ecoy]

All of a sudden my Enform screen announces "can't access CD card data" every time on start up.  If I hit the RADIO button on the lower tier of the console it disappears and the Enform screen returns to its normal read.  Been driving this IS300 for almost two years before this appeared.  What did I do to set this off?  How to rid the alert showing up?  Thanks.

[1990LS400]

Are you sure that the message says "CD" and not "SD"?  My guess is that it can't read the SD card that has the navigation maps.  Is the SD card still inserted in it's slot?