I have a problem with the 0.0.10+ world updater too.
When I open it, a command prompt opens and gives a title (Galacticraft Moon block ID/Meta changer and so on) and under that:
System.UnauthorizedAccessException: Access to the path 'c:\Users\(my user)\AppData\Roaming\Microsoft\Windows\Start...
Your game type (Server or Client): Both
Your Galacticraft Version: Newest available on micdoodle8.com (just downloaded it yesterday)
Minecraft Version: 1.47
Minecraft Forge Version: 18.104.22.1687
Error Report (if applicable):
The game mode the bug occured in: SSP, SMP, CSP and CMP (yes, I've tried...