Do you have error with ground_rock.dds or ground_rocks_a.dds? Need name of texture exactly.
If name - ground_rock.dds, you have older textures.brf file inside your compilation, i think.
UPD. Anyway, just play clean patched version GP and look for these errors. No errors - problem with another component of your compilation. You may try install these mods step by step and look for errors.