I installed Doom Builder. The engine I need to use is GZDoom so I downloaded that along with the .cfg files which I put in the Doom Builder installation directory. When I attempt to start a new project I get an error after the initial configuration:
WARNING: You have no IWAD file set for this configuration!
WARNING: Could not find required lump PLAYPAL
I did put the DOOM2.WAD in the Doom Builder directory. What did I do wrong?