Whats with this triangle error and how would u fix it???

heres da debug:

08.14.11 00:18:46 tool pc 01.00.00.0609 ----------------------------------------------
08.14.11 00:18:46 reference function: _write_to_error_file
08.14.11 00:18:46 reference address: 42ca20
08.14.11 00:18:46 Couldn't read map file './toolbeta.map'
08.14.11 00:18:46 i'm going to render debug lightmaps for drought of levels\drought\drought, and i'll stop when red+blue+green = 0.900000.
Hit control-c now if this isn't right.
08.14.11 00:18:47 WARNING: 1 clusters in structure_bsp levels\drought\drought have no background sound or sound environment.
08.14.11 00:18:47 start levels\drought\drought
08.14.11 00:19:07 0.000000
08.14.11 00:19:09 radiosity error: smooth triangle group too big for page levels\drought\shaders\drought_walls
08.14.11 00:19:10 EAX: 0x00000000
08.14.11 00:19:10 EBX: 0x00000101
08.14.11 00:19:10 ECX: 0x00000000
08.14.11 00:19:10 EDX: 0x00000000
08.14.11 00:19:10 EDI: 0x0018F9A0
08.14.11 00:19:10 ESI: 0x00000000
08.14.11 00:19:10 EBP: 0x0018F878
08.14.11 00:19:10 ESP: 0x0018F868
08.14.11 00:19:10 EIP: 0x77CF0C32, 83 C4 04 C2 ?????
08.14.11 00:19:10 EXCEPTION halt in \halopc\haloce\source\tag_files\tag_groups.c,#3157: #-1 is not a valid structure_bsp_material_block index in [#0,#0)