THINGS NOT FOUND error!

I built a new map in doom builder 2. When i test it in doom builder 2 it runs ok but if i run it within a port it crashes after i choose difficulty and says THINGS NOT FOUND. What is wrong here?

Taking a couple of wild guesses - you forgot to load a resource wad along with your map wad or unticked some difficulty settings when placing player starts. Which port is this for and did you save an error log?

I guess i did something wrong with the MAPINFO file, i erased it and then wrote it again and it worked fine!

Perhaps you placed it between MAPXX and THINGS lumps? I think it's important to not interfere with the order of map specific lumps like LINEDEFS, SEGS, etc.