Hi Ola, the current version of MoI is still a 32-bit program and so it's limited in the size of file that it can import. 500MB is pretty big and it looks like you're running out of 32-bit address space while loading it.

One thing you can try is to loosen the display mesh density, go to Options > View > "Meshing parameters" and set "Mesh angle" to a looser angle like 30 degrees and uncheck "Add detail to inflections". That will produce a rougher display mesh but will also consume less memory so it may be possible to load the file after that but with your large file here it may not be enough.

This will be solved in MoI v4 which will be 64-bit and will be able to use all your system RAM instead of only a limited amount. The first beta release of v4 is getting pretty close.

- Michael