Possible corrupt waypoints.
Export your waypoint library to a memory card and load that data to HumminbirdPC. Check for corrupt waypoints and delete them.
Load the corrected list back to the memory card. Replace what is on the card.
Format Nav Directories and load the data from the card back to the unit.
Humminbird Helix 12 CHIRP SI, 1198c SI, 1198c SI, ONIX 10 SI NT, Helix 7 CHIRP SI GPS G2, SOLIX 12 SI, 360, RC-1