GeoHub NI Help - Update Map Definition
Update Active Map Definition
Within
the Map Definition dialogue, the Update Active Map Definition tool 
allows you to
save any updates you have made to an existing map e.g. if you have added another layer or perhaps changed
the symbology in some way. This means that when you come back to this map in the future, these changes
will be saved.
1. Click on the Show Map Definitions
button 
on the toolbar to open the Map Definitions dialogue.
2.
To
update your map definition (i.e. save your changes) click on the 'Update Active Map Definition' tool
. This is the tool on the right-hand side of the Map Definition dialogue.
3. This saves any changes you have made to your map definition so that they are there when you open the map again in the future. If you do not use the Update Active Map definition then any changes made will be lost when you activate another map, create a new map or log out of the Map Viewer.