Turning on the scale shows an "unst" message

When I turn on my scale shows the message “Unst” even when there isn’t an object on it. What can I do to fix it? I already replaced the batteries and it doesn’t work.

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

crwdns2934109:0crwdne2934109:0

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