Which channels did you save to the sim?
I’ve heard that the Velocity channel can cause memory issues in certain versions of Fume. In theory, adding a Krakatoa FumeFX modifier onto the sim should allow you to prevent velocity from loading by unchecking the velocity channel.
P.S. I’ve just finished some modifications to the FumeFX handling that should make life easier. In the new version (that will be beta’d soon) you only need a FumeFX modifier to specifically disable channels, which is opposite of the current version. It’s also a little smarter about getting rid of memory it doesn’t need anymore. I’ll see if that helps the situation out.
It should be in the standard modifier list as “Krakatoa FumeFX”. If you don’t see it, let me know the version string in the title bar of the Krakatoa GUI.