Hi,

I tried running Scratch image with the current VM and found that it bombed 
with cryptic "a primitive failed" message. Not that I expected to work 
smoothly but I was surprised about the root cause - many numbered primitives 
in primitiveTable (unix/src/vm/interp.c) were replaced with primitiveFail 
instead of being redirected to their respective named primitive. In my case it 
was primitive 207 (primNetNameResolverStatus).

Any reason why new VMs let primitives fail rather redirect them?

Is backward compability maintained only across the same major version of the 
VM?

Should images warn if they are opened in a VM that may not be compatible?

Subbu