If you're having troubles seeing textures in our maps, you might want to try this textures pack.
Download Sylloc-Server textures pack
Some of the maps have been compiled several years ago. It might seem reasonable to think that Half-Life 2 Deathmatch has had its share of updates, thus making some textures going wild... Note that newer maps should work properly!
Instructions:
You will find here the latest versions of Sylloc Maps, designed by Venin. Except for ma_sgtc maps, which were made by the Mappers-Alliance and dm_abydos, by Jejebond.
All these maps, as you may know, are Stargate related. You can play on them using Half-Life 2 Deathmatch (HL2DM), and copying the maps in your /hl2mp/maps directory.
Note that the maps are bzip2 compressed.