I am a user who ran into the following error after installing ModelGUI in C:\Program Files:
C:\Program Files\mgui-1.0.21-alpha>java -Djava.library.path=bin\amd64 -Xmx2000m -classpath .;*;lib;lib\* mgui.interfaces.exec.MguiStart
2014.03.15 06:32:41 EDT: Error initializing ar.model environment from ’C:\Program Files\mgui-1.0.21 -alpha\init\mgui.default.init’
2014.03.15 06:32:41 EDT: Fatal error: Could not initialize InterfaceEnvironment.
Windows is likely giving a permission error because it is trying to write a log file in Program Files. There are 3 ways to fix this, starting with the most recommended:
1. Move everything to a another folder where there are no permission issues. A folder somewhere in "My Documents" should work without issue.
2. Look in C:\Program Files\mgui-1.0.21-alpha\init for a file called "mgui.default.init." Use a text editor (e.g., Notepad) to edit this file with the two following changes:
a. Put a "#" in front of the line "setLogFileAndConsole mgui_session"
b. Type on the next line "setLogConsole"
This will prevent the program from trying to print a log file.
3. Run the bat file, shortcut, or command prompt as an Administrator.