Hi @helenaax2r and @1119,
Here are the most recent UNITE database ghost trees. 
There is an issue in ghost-tree that I will fix soon and you can find the details here if you are interested. Basically, the pre-built trees are good to go and formatted correctly, but the software needs to be modified so it adds quotes to the IDs in the Newick to allow underscores that are in the new UNITE accession IDs. I will do that next and improve docs.
If you have any questions, please let me know, especially while documentation is sparse!