"Not Ready" keeps popping up.

When I try to load up my files from my zip card, a “not ready “ message comes up on the screen. How do I fix this? I can't load up anything from any of my cards.

crwdns2934089:0crwdne2934089:0 crwdns2934093:0crwdne2934093:0

crwdns2934109:0crwdne2934109:0

crwdns2889612:0crwdne2889612:0 0
crwdns2934285:0crwdne2934285:0