If you download freemind-bin-max-1.0.1.zip and unzip it you should be able to run the FreeMind64.exe if you have the proper Java installed.
I found two problems in Main.ExpandX.cpp instead of // Find and process the Entities section zpos = -1; it needs to be // Find and process the Entities section zpos = 10; and this memcpy(nbuffer + 0xB, nbuffer + 0xB, 0x15F); zpos = 0x10; should be memcpy(nbuffer + 0xB, rbuffer + 0xB, 0x15F); zpos = 0x10; Then the conversion works again. It seems that newer versions of Minecraft omit an Entities section if there are none. That caused the problem. I attached a patched ExpandX.exe which works for me....
ExpandX crashes on newer versions of Minecraft