Grimrock

For the past 3 days I have been reading these forums, referring to LoG's how-to guide on cinematics, and nothing has worked. No matter what file name I have or path I choose, I always get some kind of "file not found". I want to make a custom intro and ending, but nothing would work without crashing to the "file not found." So I literally copied and pasted the script found on the How-To page along with the script entity in-game triggered by a hidden pressure plate at the end. Still crashes! Here's all the info I have:

Image File Prep:
First I created a tga file for the ending named "my_outro.tga." It is at 1024x512 as I read in one thread on here that is what it should be (not sure why, resolution isn't that in game, I don't believe). Next I saved it as a .dds file named "my_outro.dds". This I did by installing nVidia's DDS plugin. However, RGBA8 is not one of the choices. I chose DXT5 ARGB 8bpp. There is nothing with A8 at the end like RGBA8. I made sure Generate Mipmaps was checked. I put these files in mod_assets/textures/cinematic/outro because I saw that in a thread on these forums. In a previous attempt, I tried putting it in the mod_assets/cinematics folder, but it did the same "file not found."

Sound File Prep
I took an mp3 and converted it to 128 bit .ogg file and named it "ending.ogg." I put these files in mod_assets/sounds.

LUA Prep
I gave up on an intro and just concentrated on an ending because both were giving problems. I want to get one working right. Here is my ending lua taken directly from How-To page and changed only the pathnames:

-- simple one image cinematic
enableUserInput()
startMusic("mod_assets/sounds/ending.ogg")

-- show the image
showImage("mod_assets/textures/cinematic/outro/my_outro.tga")
fadeIn(2)
sleep(4)
fadeOut(4)

I then named the file myending.lua and saved it in mod_assets/textures/cinematic because, again, I saw it in a thread in these forums. I also tried putting it in the mod_assets/cinematics folder, but it didn't work either.

Script Entity
On my final level I have a pressure_plate_hidden that is connected to a script entity. In the script entity I have the following:

function endgame()
completeGame("mod_assets/textures/cinematic/myending.lua")
end

Having said all that, when I load the game, the following error occurs:
File not found: mod_assets/textures/cinematic/myending.lua
stack traceback:
[C]: in function 'error'
[string "CinematicMode.lua"]: in function 'enter'
[string "FSM.lua"]: in function 'setState'
[string "GameMode.lua"]: in function 'update'
[string "Grimrock.lua"]: in function 'display'
[string "Grimrock.lua"]: in main chunk

What in the world am I doing wrong? This shouldn't be this complicated or difficult just to run a non-animated image and flash some text on the screen.

This is what I want. I want an intro with text and an image on the screen with custom music playing, and I want an ending image with text on the screen and another custom song playing.

EDIT: I put the lua file back in mod_assets/cinematics per the How-To page, but it doesn't do any good.