"GFZROCK texture" doesn't show up

I was doing a test map in SRB2DB2, but I always have errors when testing a map in this map editor so I loaded the map in SRB2 Doom Builder to test it out, but the walls of my map shows the GFZROCK textures as “Unknown texture”: http://i57.tinypic.com/10e216d.png .

Testing the map would show GFZROCK textures, but it bothers me that I can’t see it in the editor.

Then I loaded the map in SRB2 Workbench, and I had the same problem: http://i57.tinypic.com/2cn6y6v.png .

Finally, I opened SLADE3 and loaded srb2.srb. I typed GFZ in the filter and guess what? It doesn’t show up either: http://i62.tinypic.com/5dwhll.png (GFZROCKB is a different texture).

It does show up in SRB2DB2 and DB2, but as I said before, it bothers me because SRB2DB is one of the map editors I use the most and I use GFZROCK as a “placeholder” when I don't know what texture I want to add to a wall.

EDIT: Thank you Neo Chaotikal!

Could always use 2.0.7's IWAD for now if you really want to use SRB2DB1.

As for GFZROCK, at some point Prime or someone decided GFZROCK should be split into several patches, one for each of the two basic colored blocks involved used twice. That'll be why you don't see it, it's now a texture comprising several patches.

Or you could make a copy of srb2.srb and convert the TEXTURES lump back to the old format. Should be one click in SLADE.