Yeah, start.map has no intermission screen. How does that work again? 

I think it's "spawnflags" "1" on the trigger_changelevel for no intermission 

"Intermission": Solved trouble!
that's I complicate me with the language.
I use google trans but I don't believe so much in it. 

... apparently. I could have sworn that when I previously made a brush into a func_door in TB, it would move (or "open") when the player approached it if I didn't tinker with the default entity values.

Now I've just made two bog-standard door-shaped brushes inside an arch and turned both into func_door, and when my player character approaches or even touches them, nothing happens. Each func_door is 64 units wide and "lip" is set to 8. I've tried changing "lip" to a different value and changing "angle" to a different value, but to no avail. Am I missing something obvious? 

Try creating simple box, make it func_door and test. If it works - start adding keys and check if any will break it. 

Did you add a targetname? 

A door "not opening" is usually because it has a targetname like necros stated. Do not give the func_door any keys except for an angle for testing. 

check 'Don't link' spawnflag. It usually fixes all problems if door doesn't open (if there are other doors nearby) 

The is_linked flag breaks double doors if turned on and they're targeted. 

No I did not add a targetname. I did not touch the default entity settings at all (except for changing the angle and lip in desperation, but this was after things didn't work).

I didn't link them either, at least not as far as I know. What should the "Key" and "Value" fields be for unlinked doors? 

linking is automatic.

first, put the 'door don't link' flag on both of the doors, test and see if it moves. 

In TB, there are these "Key" and "Value" columns, e.g. "classname" (Key) and "worldspawn" (Value). Which Key/Value combination should I specify to put a 'door don't link' flag on both doors? (Sorry to have to ask you to re-explain).

What I did try in the mean time was to turn one of the func_doors back into a world brush, figuring that if there's just one, there's no way it could be linked. But that didn't solve the problem either... 

total newbie

spawnflag 4 is what they mean 

That didn't work either, though. Odd. 

it sometimes breakes with angle = 0. Try an angle that is different from zero. 

Tried various angles; no luck.

I've just created a new brush and converted it to a func_door, and it's the same story. When I don't touch the default Keys & Values, it just doesn't work.

This is what TB shows me when I create a brand new func_door. Is there anything there that I should change? So far I've tried changing the values of the keys "lip", "angle" and "spawnflags" (from "0" to "4"), but to no avail...

By the way, thank you very much to everyone who's responded so far. 

I made a door in gtkradiant, tested it just to be sure it is working and opened map in TB.
Here is what it looks like
https://i.gyazo.com/32870bdc8156910a054ccb3a843f9a8a.png

Maybe try voodoo magic tricks if nothing else works?
Can you remove all over keys except classname and spawnflags ans check if it helped? 

TB doesn't allow me to remove any of the default keys; I can just change the value.

Anyway, I've finally managed to create a working door elsewhere in the same map. The strange thing is, though, that I've created it in exactly the same way as the first one -- the brushwork is even almost identical. The first one still doesn't move at all, though.

I'm completely confused now. 

 

yes, it's very likely because of door linking.

doors link automatically if their bounding boxes are touching. what is happening is a door nearby has a targetname which is causing your new doors to link and also require a trigger to open. 

I have specified no targets or targetnames anywhere in this map; the door (or set of doors) was the first brush entity I created in the map. Everything else was just world brushes and one info_player_start.

I can copy and paste just the door, arch and floor brushes into an empty .map file and get the same result. In fact, I just tested with a brand new map, making the simplest of doors with just 4 world brushes and a single func_door, and it still doesn't work.

This is what this new test map looks like in a text editor:

// Game: Quake
// Format: Standard
{
"classname" "worldspawn"
{
( -304 -64 -16 ) ( -304 -63 -16 ) ( -304 -64 -15 ) __TB_empty 0 0 0 1 1
( 656 64 16 ) ( 656 64 17 ) ( 656 65 16 ) __TB_empty 0 0 0 1 1
( -64 -320 -16 ) ( -64 -320 -15 ) ( -63 -320 -16 ) __TB_empty 0 0 0 1 1
( 64 400 16 ) ( 65 400 16 ) ( 64 400 17 ) __TB_empty 0 0 0 1 1
( 64 64 16 ) ( 64 65 16 ) ( 65 64 16 ) __TB_empty 0 0 0 1 1
( -64 -64 -16 ) ( -63 -64 -16 ) ( -64 -63 -16 ) __TB_empty 0 0 0 1 1
}
{
( 464 208 208 ) ( 496 -192 208 ) ( 464 -192 208 ) __TB_empty 0 0 0 1 1
( 464 -192 16 ) ( 464 208 208 ) ( 464 -192 208 ) __TB_empty 0 0 0 1 1
( 496 -192 208 ) ( 464 -192 16 ) ( 464 -192 208 ) __TB_empty 0 0 0 1 1
( 496 208 16 ) ( 496 -192 208 ) ( 496 208 208 ) __TB_empty 0 0 0 1 1
( 464 208 16 ) ( 496 208 208 ) ( 464 208 208 ) __TB_empty 0 0 0 1 1
( 464 48 128 ) ( 464 32 128 ) ( 592 32 128 ) __TB_empty 0 0 0 1 1
}
{
( 464 -192 16 ) ( 464 208 208 ) ( 464 -192 208 ) __TB_empty 0 0 0 1 1
( 496 -192 16 ) ( 464 208 16 ) ( 464 -192 16 ) __TB_empty 0 0 0 1 1
( 496 208 16 ) ( 496 -192 208 ) ( 496 208 208 ) __TB_empty 0 0 0 1 1
( 464 208 16 ) ( 496 208 208 ) ( 464 208 208 ) __TB_empty 0 0 0 1 1
( 464 48 128 ) ( 592 32 128 ) ( 464 32 128 ) __TB_empty 0 0 0 1 1
( 464 64 96 ) ( 592 64 64 ) ( 464 64 64 ) __TB_empty 0 0 0 1 1
}
{
( 464 -192 16 ) ( 464 208 208 ) ( 464 -192 208 ) __TB_empty 0 0 0 1 1
( 496 -192 16 ) ( 464 208 16 ) ( 464 -192 16 ) __TB_empty 0 0 0 1 1
( 496 -192 208 ) ( 464 -192 16 ) ( 464 -192 208 ) __TB_empty 0 0 0 1 1
( 496 208 16 ) ( 496 -192 208 ) ( 496 208 208 ) __TB_empty 0 0 0 1 1
( 464 48 128 ) ( 592 32 128 ) ( 464 32 128 ) __TB_empty 0 0 0 1 1
( 464 -64 64 ) ( 592 -64 80 ) ( 464 -64 80 ) __TB_empty 0 0 0 1 1
}
}
{
"classname" "info_player_start"
"origin" "392 -0 40"
"angle" "-0"
}
{
"classname" "func_door"
{
( 472 -192 16 ) ( 472 208 208 ) ( 472 -192 208 ) __TB_empty 0 0 0 1 1
( 496 -192 16 ) ( 464 208 16 ) ( 464 -192 16 ) __TB_empty 0 0 0 1 1
( 480 208 16 ) ( 480 -192 208 ) ( 480 208 208 ) __TB_empty 0 0 0 1 1
( 464 48 128 ) ( 592 32 128 ) ( 464 32 128 ) __TB_empty 0 0 0 1 1
( 464 64 96 ) ( 464 64 64 ) ( 592 64 64 ) __TB_empty 0 0 0 1 1
( 464 -64 64 ) ( 464 -64 80 ) ( 592 -64 80 ) __TB_empty 0 0 0 1 1 

In a trigger_teleporter I don't know how to use the target and targetname... 

http://lmgtfy.com/?q=quake+trigger_teleporter 

Use angle "-1" for up and "-2" for downward door.
An angle of 360 won't work, either as because the door can only move 90 or 270.

See here for your map.

:P 

Thanks, Jneeraz