Cannot seem to save the Global User Mapping in Content Matrix.
The mappings are not preserved when running the migration job.
In the Global Mappings Window, before importing any xml file for manual user mappings, ensure that you load a source site by choose any site in the "Source:" drop down and wait for the grid to fetch/populate the users. from source. It's required for the windows grid to load and populate to be able to write back.
Note: You can load any source site and loading user mappings is a one time activity as it stores the mappings globally and gets applied on all site migrations by default.
