Pierre, I have had the same problem for several years. It appears when trying to search the index for certain surnames. For several years it was just one surname, but lately it is happening with searches on 4 surnames that I know of. My tree has grown very large, at 199,400 people. The latest to "crash" the tree is Carter, and it didn't happen until I reached the William Carters. This seems to be a new flaw that popped up this week. In fact, in the latest case, a strange set of gibberish that looks like alien characters, and of bold contrast, is now present in "the place of birth" column. I don't think anything like this happened with the other 3 surname flaws, but all four freeze the tree when searched. At this point the only thing to do is to delete the tree, including from the recycle bin, then replace it with a flash drive backup tree. I would love to know how to fix the flaws. The "delete people" function under "file" is not an option, since it requires using the scrolling index. If I could identify where the flaw is by ID #, and delete that person, perhaps that would be a help, but how does one know which person?