I can't run queries on pgAdmin4 on Ubuntu 19.04. I can view data through pgAdmin and execute queries through my terminal. However, whenever I try to use the query tool I get the error not enough values to unpack (expected 5, got 4).
I've tried reinstalling pgAdmin and psycopg2. Following this guide https://www.osradar.com/how-to-install-pgadmin-on-ubuntu-19-04/
I had the same problem on Debian Buster. I had psycopg2 installed through pip3 to solve the older problem with no returns in pgadmin on Debian.
So now i went to pgadmin config (right mouse button to pgadmin icon in tray) and deleted the custom path to python libraries. After that it works great.