Have attempted to load waypoints taken from another Humminbird unit onto two Gen 3 Helix 9s. One of them loads just fine but the other Helix freezes up when the SD card is inserted. Tried Factory Defaults reboot but the troublesome unit still freezes the screen, have to disconnect power to restart. Have also tried loading a Boat Lanes chip and the unit freezes up with this attempt also. The same SD card has successfully transferred waypoints to unrelated Humminbird units so don't think the SD card is the problem.

Any ideas on what to try on unit that works fine in all ways but freezes when attempting to import waypoints from multiple SD cards that work on other units?

Thanks

save all your waypoints to an sd card off the unit that freezes up. Then format nav directories. This will erase all nav data. Then try and load new waypoints. If that works then you may have a corrupt waypoints causing an issue. Humminbird PC can help identify the faulty waypoint

Load "hummingbird pc" software onto your computer (it is free online).. Read the SD card, and it might give you some help. I had several warnings when I copied another persons SD card. Some of the data had problems. It at least gave me some help in identifying bad waypoints. ALso, you might try backing up the data to a new 32gb sd card. I think they do not like SD cards that are bigger than 32bg.. (you might verify the size, should be in the manual).