Okay so here's the situation. I wanted to tie all the walls, ceilings, and floors in my map to func_detail. So I checked the "hide items" option, selected all the walls, ceilings, and floors from the top view, and tried to tie them all to func_detail at once. But the problem is, now whenever I try to select ONE wall, or ONE floor, it selects everything. I tried ungrouping them, but that doesn't seem to work. On top of that, whenever I try to test the map, everything is black and I can't move
I even tried undoing EVERYTHING and it still doesn't work. Please help me. I spent so much time on this map and I don't want it all to go to waste because of one dumb mistake 