Your comments

What I'm really saying is that after 4 years of no updates, or even a "This is what I'm working on" post, the project looks dead. That's not to say it's broke, but it's certainly not an "active" project.

2 years later and still no updates.. I get that Tom is the only person working on this (by his own choice), but if there haven't been any public facing updates in 4 years, this project does seem well and truly dead.

Tom, please release something or opensource this bad boy.

I figured out what I was doing wrong. When I copy/pasted the last user in the .json file, I copied the name, password hash, and the line after (which was an end bracket). What I needed to do, was copy the user info and the line above it. All is working now and this can be closed.

I've resolved this thanks to the comments on this post.

Thank you Jack, this fixed the issue I was having here.

Oh, I did go into the preferences.json file and manually set   "reverseProxyPrefix" : "ubooquity",

Also, maybe the ability to set customer themes on a per-user basis would be nice. For instance, I have the "No-download" theme which removes the download button. It would be cool if I could assign this theme to some users, but assign the standard theme to others that I think should be allowed to download items.
This isn't nearly as big of a deal as user-set passwords, but it would still be a nice feature.