When collapsing nodes, cloning them or selecting extension elements for nodes, the mappings within the collapsed nodes disappear after saving and reopening the mapping.
It seems like the collapsed nodes are not saved?
The "Tree Expand Level for Optimized Loading" is not set to a high enough value
1. Open the Data Mapper .
2. Go-to Advanced properties.
3. Move over to the Mapping XML text area.
4. In text area where the Mapping XML is defined , there is a property named as <TreeExpandLevelCount>6</TreeExpandLevelCount>.
5. Please update the value defined in this property to be 6 .(Default value is 3)
6.Save and open the Data Mapper . The mapping should be retained.