My map compiles just fine, but when I try to look at a prefab in Radiant, such as a spawner barricade, it's completely invisible, the only way to select it is with pressing I, but I can't specifically deselect it.
I don't know if the compiler is checking for the sound files, I have been getting an issue like that, what I did was I force the .csv to throw an error and then control+Z-ed to fix the file. For some reason it worked for me, it's worth a shot.
Try raising the ladder brush to 72" (the height of the player model) off of the floor you want the player to land on, and if that doesn't work, try making the brush flush with the floor. Not sure if this helps.
The zombies not walking on the ground part is a weird glitch I got once, try making sure your sky box related brushes are in the original order they were when you made the map and not overlapping. If you cant get it back, just delete your current map (you can copy paste whatever you already made or prefab it) and make a new one.
I'm not sure about the screen glitches with barriers, but if walls and whatnot are disappearing, just make sure there's a path that light can pass through the area where the player is.
Textures can be a bit screwy, very few textures don't work, but those are the textures on some models, but those will most probably go unnoticed.
So i tested a whole bunch of things, and determined that the game isn't even checking the .csv and/or sound files, because when I switched the names of the puzzle_2 sound, and the sound of puzzle_3, and told the game to play puzzle_2 (formally puzzle_3), its played the original puzzle_2 sound. Any idea as to how to fix the compiler?
I'm making a puzzle map that plays a sound when you open a door. 2 out of 3 of the current triggers work perfectly, but the third trigger runs the second function, but doesn't play the sound. The sound files are all .wav's and set to 48000Hz. I've tried copying another sound file that should 100% work, but nothing seems to do it. Thanks in advance :)