What do you do when you place vehicles in a map, compile it, and they don't show up in the game? This is happening to me with not only vehicles that come with the HEK like the Warthog and Banshees, but also with tags I download, like the LAAG Turret and Rocket Launcher Turrets. Any ideas on why this might be happening and how I could fix this annoying problem?

For classic vehicles:

-Make sure the slayer allowed, CTF allowed, etc checkboxes are checked.
-Make sure the slayer default, CTF default, etc checkboxes are checked.

For custom vehicles:

-Make sure the above conditions are met.
-Make sure that you added them into your globals, or scripted them to appear.

The classic vehicle requirements are there, and some of the vehicles DO actually appear. Just not all of them. And about the custom vehicles, What is the globals thing you mentioned? I'm not too experienced with adding new tags.

Open up tags\globals\globals.globals. Scroll down to vehicles, and you will find 6 vehicles in the dropdown list. Replace one of them with the vehicle you want.

Note: You cannot add vehicles into the globals, nor remove them. There must be 6.

So in reality, there can only be 6 vehicles per map? Or am I confused? I'm sorry.
And when I have the globals.globals open, do I just delete one and add another?

There can only be 6 types of vehicles, unless you script in the extra ones.