Hey,
Not sure how often this was posted yet but yeah I have no idea on how to solve it and when trying to find anything there are only old posts and nothing has helped so far.
So I am trying to make my own models and I tried to add some simple things for my gmod map I'm working on. I created some candles, A beam structur I premade in the hammer.exe/source SDK and imported into blender to then export to create a model. So far so good. Now I decided to try to add an orange texture to the pumpkin I made and all I can manage is to get the same missing pink and black texture.

So I followed this tutorial. https://www.youtube.com/watch?v=Dam1fy5Bi7A
I know it's pretty old but it gave me most of the tools I needed to get the first models into my map. So I did as he did. I named everything in blender (version 2.81.16) the same. The model is called Pumpkin_1 and so are the project data (the green triangle) and the materials. Then I export via the Blender Source Tool as SMD. Export Path = a path onto my USB-Stick but no spaces used. The Engine Path is "G:\Steam\steamapps\common\GarrysMod\bin\" as I use that as my steam game library. Target Engine was set to source and that is all. So when I export I get a nice Pumpkin_1.SMD file which then gets a qc file from me with the following text inside.

Originally posted by author:

$modelname "Varmints_Models/Pumpkin_1.mdl"
$model "Body" "Pumpkin_1.smd"

$staticprop
$cdmaterials "models/Varmints_Models/"
$surfaceprop "Pumpkin_1"

$sequence "idle" "Pumpkin_1.smd"
$collisionmodel "Pumpkin_1.smd" { $concave }

That is basically the same as in the video.

Then I move the SMD file + QC file onto the Studiomdl.bat which was also created due to the video and contains the following text.

Originally posted by Author:

"G:\Steam\steamapps\common\GarrysMod\bin\studiomdl" -nop4 -game "G:\Steam\steamapps\common\GarrysMod\garrysmod" %1
pause

Then it opens a window, has a lot of "Warning: Model has 2-dimensional geometry (less than 0.500 inches thick on any axis" and then it gets this text.

Originally posted by author:

Collision model completed.
---------------------
writing G:\Steam\steamapps\common\GarrysMod\garrysmod\models/Varmints_Models/Pumpkin_1.mdl:
Loading preexisting model: G:\Steam\steamapps\common\GarrysMod\garrysmod\models/Varmints_Models/Pumpkin_1.mdl
Found 1 preexisting sequences.
bones 964 bytes (1)
animations 112 bytes (1 anims) (1 frames) [0:00]
Building sequence index remapping table...
No re-ordering required.
sequences 220 bytes (1 seq)
ik/pose 164 bytes
eyeballs 0 bytes (0 eyeballs)
flexes 0 bytes (0 flexes)
textures 72 bytes
keyvalues 0 bytes
bone transforms 0 bytes
Collision model volume 81828.46 in^3
collision 0 bytes
total 1752
---------------------
writing G:\Steam\steamapps\common\GarrysMod\garrysmod\models/Varmints_Models/Pumpkin_1.vvd:
vertices 129648 bytes (2701 vertices)
tangents 43216 bytes (2701 vertices)
total 172928 bytes
---------------------
Generating optimized mesh "G:\Steam\steamapps\common\GarrysMod\garrysmod\models/Varmints_Models/Pumpkin_1.sw.vtx":
body parts: 8 bytes
models: 20 bytes
model LODs: 12 bytes
meshes: 9 bytes
strip groups: 25 bytes
strips: 27 bytes
verts: 24309 bytes
indices: 5760 bytes
bone changes: 16 bytes
everything: 30210 bytes
---------------------
Generating optimized mesh "G:\Steam\steamapps\common\GarrysMod\garrysmod\models/Varmints_Models/Pumpkin_1.dx80.vtx":
body parts: 8 bytes
models: 20 bytes
model LODs: 12 bytes
meshes: 9 bytes
strip groups: 25 bytes
strips: 27 bytes
verts: 24309 bytes
indices: 5760 bytes
bone changes: 16 bytes
everything: 30210 bytes
---------------------
Generating optimized mesh "G:\Steam\steamapps\common\GarrysMod\garrysmod\models/Varmints_Models/Pumpkin_1.dx90.vtx":
body parts: 8 bytes
models: 20 bytes
model LODs: 12 bytes
meshes: 9 bytes
strip groups: 25 bytes
strips: 27 bytes
verts: 24309 bytes
indices: 5760 bytes
bone changes: 16 bytes
everything: 30210 bytes

Completed "Pumpkin_1.qc"

F:\Blender\Varmints_Models>pause

So now that it is done I also try to check it with the hlmv.exe inside the gmod bin folder but there and of course also inside the map editor it only shows me a pink and black pumpkin. :C

The error message in hlmv I get when checking in the model section is

Originally posted by Author:

*** ERROR *** Model attempted to load one or more VMTs it can't find.

So now after all my search I came to nothing useful and I am ready to take any help I can get to get this problem solved.

Btw using Windows 10 Pro in case that this is of any relevance.
Thank you in advance for your help.