Go into your library
Right-click manaCompiler
Mouse over "Manage"
Select "Browse Local Files"
Find manaCompiler.exe
Right-click on manaCompiler.exe and select "Properties"
In the window that popped up, select the "Compatibility" tab
Tick the box "Run the program as an administrator"
Select "Run this program in compatibility mode for: Windows 8"
Select "Apply"
Select "OK"
Launch the program.