Problem with addon material

Every time I try to make a new prop I have a problem with the material it doesn’t always show up with the skin I made, it just shows up as the purple/black error. I have no idea what I’m doing wrong I fix up the vtf file by changing the name of the file and use photoshop to change the skin to what I want. I also change the vmt’s name into the desired name I want, which is going to be same name as the vtf open the vmt in notepad. Change the base texture into the path which is the file the vtf and vmt are in and then write the name of the vtf and vtm example: “$basetexture” “black\cat”
I close everything up and change the names for all of the model files into the name of the vtf and vmt