The pgAdmin 4 server could not be contacted in Linux Mint 20.2 - postgresql

Question

Folks i just installed pgAdmin 4 from here. But when i launch the application, it crashed, throwing me the following me error:
The pgAdmin 4 server could not be contacted:
pgAdmin Runtime Environment
--------------------------------------------------------
Python Path: "/usr/pgadmin4/venv/bin/python3"
Runtime Config File: "/home/toastedguy2/.config/pgadmin/runtime_config.json"
pgAdmin Config File: "/usr/pgadmin4/web/config.py"
Webapp Path: "/usr/pgadmin4/web/pgAdmin4.py"
pgAdmin Command: "/usr/pgadmin4/venv/bin/python3 -s /usr/pgadmin4/web/pgAdmin4.py"
Environment:
- GJS_DEBUG_TOPICS: JS ERROR;JS LOG
- LANGUAGE: en_US
- USER: toastedguy2
- XDG_SEAT: seat0
- XDG_SESSION_TYPE: x11
- SSH_AGENT_PID: 1388
- SHLVL: 0
- HOME: /home/toastedguy2
- DESKTOP_SESSION: cinnamon
- GIO_LAUNCHED_DESKTOP_FILE: /usr/share/applications/pgadmin4.desktop
- GTK_MODULES: gail:atk-bridge
- XDG_SEAT_PATH: /org/freedesktop/DisplayManager/Seat0
- LC_MONETARY: es_CR.UTF-8
- DBUS_SESSION_BUS_ADDRESS: unix:path=/run/user/1000/bus
- CINNAMON_VERSION: 5.0.5
- GIO_LAUNCHED_DESKTOP_FILE_PID: 2430
- MANDATORY_PATH: /usr/share/gconf/cinnamon.mandatory.path
- QT_QPA_PLATFORMTHEME: qt5ct
- LOGNAME: toastedguy2
- XDG_SESSION_CLASS: user
- DEFAULTS_PATH: /usr/share/gconf/cinnamon.default.path
- XDG_SESSION_ID: c2
- GTK_OVERLAY_SCROLLING: 1
- GNOME_DESKTOP_SESSION_ID: this-is-deprecated
- PATH: /home/toastedguy2/.local/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/snap/bin
- GDM_LANG: en_US
- GTK3_MODULES: xapp-gtk3-module
- SESSION_MANAGER: local/toastedguy2-MS-7A39:#/tmp/.ICE-unix/1316,unix/toastedguy2-MS-7A39:/tmp/.ICE-unix/1316
- XDG_SESSION_PATH: /org/freedesktop/DisplayManager/Session0
- LC_ADDRESS: es_CR.UTF-8
- XDG_RUNTIME_DIR: /run/user/1000
- DISPLAY: :0
- LANG: en_US.UTF-8
- LC_TELEPHONE: es_CR.UTF-8
- XDG_CURRENT_DESKTOP: X-Cinnamon
- XDG_SESSION_DESKTOP: cinnamon
- XAUTHORITY: /home/toastedguy2/.Xauthority
- XDG_GREETER_DATA_DIR: /var/lib/lightdm-data/toastedguy2
- SSH_AUTH_SOCK: /run/user/1000/keyring/ssh
- SHELL: /bin/bash
- LC_NAME: es_CR.UTF-8
- QT_ACCESSIBILITY: 1
- GDMSESSION: cinnamon
- LC_MEASUREMENT: es_CR.UTF-8
- GPG_AGENT_INFO: /run/user/1000/gnupg/S.gpg-agent:0:1
- LC_IDENTIFICATION: es_CR.UTF-8
- GJS_DEBUG_OUTPUT: stderr
- XDG_VTNR: 7
- PWD: /home/toastedguy2
- XDG_CONFIG_DIRS: /etc/xdg/xdg-cinnamon:/etc/xdg
- XDG_DATA_DIRS: /usr/share/cinnamon:/usr/share/gnome:/home/toastedguy2/.local/share/flatpak/exports/share:/var/lib/flatpak/exports/share:/usr/local/share:/usr/share
- LC_NUMERIC: es_CR.UTF-8
- LC_PAPER: es_CR.UTF-8
- GDK_BACKEND: x11
- NO_AT_BRIDGE: 1
- PGADMIN_INT_PORT: 42741
- PGADMIN_INT_KEY: 06b1e235-ddd0-4070-9ac4-476a972202a2
- PGADMIN_SERVER_MODE: OFF
--------------------------------------------------------
Failed to launch pgAdmin4. Error:
Error: spawn /usr/pgadmin4/venv/bin/python3 ENOENT
How do i fixed it folks?
Notes:
My OS is: Linux Mint 20.2
PostgreSQL version: 12.8 (exact version by executing psql --version is: psql (PostgreSQL) 12.8 (Ubuntu 12.8-0ubuntu0.20.04.1).
PostgreSQL service is active.

Answer 1

After upgrading from Ubuntu 21.10 to Ubuntu 22.04 (and as a result upgrading Python 3.9 to 3.10), I had the same error. While at first it seemed the issue was that the python 3.9 symlinks inside /usr/pgadmin4 were no longer linking to the correct place - but fixing those was not enough to solve the issue. It turned out that there were more dependencies to take care of.
The proper solution was that I needed to update the apt source URI link inside "Ubuntu Software & Updates" to point to the newer Ubuntu jammy apt URI:
from https://ftp.postgresql.org/pub/pgadmin/pgadmin4/apt/impish
to https://ftp.postgresql.org/pub/pgadmin/pgadmin4/apt/jammy
As soon as I did that, and reinstalled pgadmin4-desktop and pgadmin4-server using apt remove and apt install, it had all the required dependencies and all worked.

Answer 2

All I had to do was:
sudo apt remove pgadmin4-server
sudo apt install pgadmin4-server
sudo apt install pgadmin4-desktop