I had a set made for my tori, but then decided to empty it. After doing so, I realize that I've lost a Left Leg Texture Trail :/

Can you elaborate on that?
Did you delete your left leg texture trail by mistake?
If that's the case - just PM the person who sold you the texture set, and hopefully he'll have that texture file.

*The Support board is for technical cases relating to TB, by the way.

I think that the Set function has a bug, because not only did the texture trail disappear, so did two feet textures and a right leg texture (I sold a full set of textures to Zazo and it was missing the feet and leg textures after it reached him).