corrupted waypoint

Hi,

I am use mini 4pro and RC2. I create and export waypoint with mapsmadeeasy. Saved the waypoint to my RC2. Used the waypoint in my mini 4. No problem. But if I change something in the waypoint (on RC2) or just saving it again the waypoint corrupt and RC2 froze. What am I doing wrong. Can I not edit the imported kmz waypoint? 

Thanks