My asset textures keep vanishing?

Help a noob out here.

I just downloaded a landscape asset pack and it has textures and material that resets whenever I try to use them. And then they are blank in the file.
I don’t understand how that possible but it just doesn’t seem to want to work at all. Could I get a hand here???

Could you provide more details? Which pack are you using, what version of UE4, and what exact steps you took that produced the problem?

Also if this is marketplace related, you may want to post this in that forum for better coverage.