roster editing help and jersey questions

1. I tried to tweak a roster file I reditor and I recieved a error stating "It's not supported or you don't have a proper license to open it". why does that happen and is there a way to change it?

2. In one of the roster files I have all white uniforms with no logos or numbers. How do I fix that?

What kind of license do you have for the RED Modding Center? If it doesn't include full access, then there will be things that you can't edit.

I have the 2K 12 PC tables and My Friends Interfaces. Some rosters work and some don't.

Is it compatible with 2K 13 rosters?

You need to use RED Modding Center, not last year's REDitor. See the stickied release thread in the Releases & Previews section for more information.