Migrate profiles from old to the new launcher

Start up the legacy launcher
Hit key combination “Ctrl + d” and open up the app data folder
Open the “ClassicUO” folder
Copy the folder “Data” and “settings.json”
Search for the new “Ultima Online - Sagas” installation and open up the shortcut folder
Right click and open the folder path
Then navigate to “ClassicUO”
Paste the copied “Data” folder and “settings.json” here (yes on overwrite)
Start the game by using the launcher
Enjoy