Tree Creator in 2019.2.0f1 materials not working yet?

I bought some of Forst's tree packs, which look nice, but all I get is pink trees. He said to refresh them in Tree Creator, but that makes no difference.

I then tried from scratch, downloading the Tree Creator tutorial pack - same again: pink materials.

Are these shaders and materials not ready for HDRP yet? Using the HDRP 6.9.1 version. Or hopefully, have I missed something?

Also the trees I bought - some open in Tree Creator, others don't. If I am making a tree in Tree Creator, how do I re-open that tree later, if I want to adjust it. Can't find that either. Bad day - hours on this

Thanks.

 

Continuing to try to figure this, and having made some basic and rubbish trees, I see that they are not actually reopened; when you click on them, they appear in Tree Creator anyway. So I am uncertain what Forst's are. Trees should not be so hard, nor time and money wasting. Standard landscape assets, surely.

 

Did you figure it out?