If it first freezes and then crashes, it's probably unable to generate a level. Are you sure your vault has ORIENT: encompass?

The 'transparent' tag prevents the squares of the vault from being associated with its map index, and from being marked with MMT_OPAQUE. The former prevents the vault from, for example, showing up in death reports, as there is no association between the map coordinate and the vault. MMT_OPAQUE needs...