VBSP crash - can't find this error anywhere on internet

[disseminate]

Valve Software - vbsp.exe (Jul  7 2010)
8 threads
materialPath: c:\program files (x86)\steam\steamapps\disseminate\half-life 2 episode two\ep2\materials
Loading C:\Program Files (x86)\Steam\steamapps\sourcemods\garrysmod\maps\rp_sedition.vmf
ConVarRef mat_reduceparticles doesn't point to an existing ConVar
Could not locate 'GameData' key in c:\program files (x86)\steam\steamapps\disseminate\half-life 2 episode two\ep2\gameinfo.txt
Patching WVT material: maps/rp_sedition/pk02/pk02_rock01_ground01_blend_wvt_patch
fixing up env_cubemap materials on brush sides...
ProcessBlock_Thread: 0...1...2...3...4...5...6...7...8...9...10 (0)
ProcessBlock_Thread: 0...1...2...3...4...5...6...7...8...9...10 (1)
Processing areas...done (0)
Building Faces...done (0)
Chop Details...done (0)
Find Visible Detail Sides...
Merged 556 detail faces...done (0)
Merging details...done (0)
FixTjuncs...
PruneNodes...
WriteBSP...
done (2)
writing C:\Program Files (x86)\Steam\steamapps\sourcemods\garrysmod\maps\rp_sedition.prt...Building visibility clusters...
done (0)
Creating default LDR cubemaps for env_cubemap using skybox materials:
   skybox/sky_day01_09*.vmt
 ! Run buildcubemaps in the engine to get the correct cube maps.
Creating default HDR cubemaps for env_cubemap using skybox materials:
   skybox/sky_day01_09*.vmt
 ! Run buildcubemaps in the engine to get the correct cube maps.
Finding displacement neighbors...
Finding lightmap sample positions...
Displacement Alpha : 0...1...2...3...4...5...6...7...8...9...10

And that's it. It just stops at the displacement alpha calculations, but sometimes I also get an added goodie:

Too many unique texture mappings, max = 2048

Anyone have any ideas? I've tried hiding displacements etc to no avail.