The image take around 600MB before the crash but that is expected.
I've seen that this error was appearing before in the past.
Any suggestions of how to debug it?
Build a console VM (you should see PharoConsoleUnstripped.exe in build/vm, buildast/vm & builddbg/vm) and run under gdb from a console window. Make sure the Pharo window doesn't obscure the console window so you can notice when a crash happens. You'll then be able to get a backtrace, see where the illegal access is, what the system is trying to do, etc.
If you're lost in gdb, when you get the crash Skype me and we can try and look at it together.