Hi markelliot2002_x_yahoo_x_com,
Please have a look if this file works for you:
https://www.amazon.com/clouddrive/share/nuoF2QoQl3KJFTJM8zKnKYkB1eedpSK5RPwZiuq6w9B
I had to download the file from Mixamo, as I had no textures here. (File> Save Project with Assets…) creates an excellent package.
I’m not familiar with Adobe Captive, I have to dig deeper into its manual, so far I haven’t found any hints why an alpha channel is not in use.
If you like to have just a single color background, or just while, use the sky object, and new material. Let me know if you want to have an example.
You asked how to scale a character. There are several ways. Let’s start with the simplest, for now, I hope that will work for now and your project. Create a null and drag the joints as well as the polygon object under it. Then set the scale to, e.g., 3 for all three axes. I have done it here, as I “never” answer from memory, and it works fine here with Mousey. (Side note: do not use the Group-Short-Cut here. In fact, if there is any animation involved, ALWAYS do it manually.)
Cheers