FYI, I just “reproduced” it once though cannot every time, I highly doubt it caused by one of…
- I digged some “holes” on the landscape by “Delete” tool from the “Manage” panel.
- I am used to backup map by “Save As” to another map name but without making a copy of “xxx_sharedatasets” folder, then somehow I opened and edited one of “older” map with newer “xxx_sharedatasets”.