Executable: Risen3D ßV1.7.00 Oct 13 2005
OS: Windows XP 5.1.2600
Z_Init: 32.0 Mb allocated for zone.
Game path: G:\games\doom2\risen3d\
EDIT MODE: OFF
UDIR: none set
SAVE PATH: G:\games\doom2\risen3d\savegame\
Building gl nodes for g:\games\doom2\cd\crudream.wad
NODES BUILD: error Input/output error
Shutting down: A B C D E F G H I N Complete

Boom-compatible, huh? Thanks for the useful error message too. N stands for-