Just figured out what I was doing wrong. I couldn’t log in with any of the code before guestbook-profile, but at guestbook-profile it started working again.

My error: I was using the same database with everything. The database used in the last part of the book has JSONB added to it, and JSONB stuff in the code to deal with that. So when I ran code from the first part, the code didn’t have the JSONB stuff, but the database had it, so it wasn’t working.

Solution: If I add the json library to the project.clj file, and change db/core.clj according to the guestbook-profile instructions, and I also updated the queries to be safe, now I can log in fine.

Leaving my post up in case there are other newbies like me who are new to JSONB and how that affects the database and code.