Error list for Peter Webb, Subgroup complexes, pp. 349-365 in: ed. P. Fong, The Arcata Conference on Representations of Finite Groups, AMS Proceedings of Symposia in Pure Mathematics 47 (1987). The most significant mathematical errors occur on pages 352 and 357. page 350 line -7: an edge is missing in the drawing of the simplicial complex. page 352 line 9: it is simply incorrect that the complex of normal chains in B_p(G) may be included in the statement of Theorem 2.3. I am grateful to Serge Bouc for pointing this out. page 353 line 7: it should say that if G is a non-cyclic finite simple group then S_p(G) is not contractible. page 355 line 11: it should be Theorem 3.1. page 355 line -14: there should be edges joining the vertices in a straight line. page 357 line 11: in Z_p Z G_\sigma the middle Z should be deleted. page 357 line 21: for A_7 the Steinberg module is -(2P_{20} + P_{14}). page 357 line 23: for M_{12} the Steinberg module is 2P_{44} + P_{16a} + P_{16b} + 4P_{144}. I am grateful to Steve Smith for this calculation. page 359 line 13: in the indexing of the inner sum it should be G_x. page 364 line -8: it should be by.