i have use this prog in my quest
it works fine and it's a good tool for uploading multiply maps (not locked)
it can upload only one locked map for the time cause it handles only one serial number
about your prob
i think i know why you get the runtime error
when trying to upload on a sd card, a popup "save to" window will open
DO NOT use it until the % of the map building is finished (you can see it at the background)
once is finished just press save
hope i helped