Download and install JMRI®
JMRI Setup and Installation
JMRI environments...
Release Notes
Supported Hardware
Devices, command stations, networks, and protocols:
Source Code
Issues

JMRI Help:

Contents Index
Glossary FAQ

Donate to JMRI.org

Release Notes for JMRI 4.22 release

Date: March 1, 2021

From: Bob Jacobsen

Subject: Production Release 4.22 of JMRI/DecoderPro is available for download.

We are very pleased to announce that the 4.21 series of JMRI test releases has resulted in a version that's good enough to be recommended for general use, including by new users. We're therefore making that version, "Production Release 4.22" available for download today.

Notes:

JMRI is now only available under the GNU General Public License. For more information, please see our copyright and licensing page.

Update From Older JMRI Versions

If you are currently using a version older than JMRI 4.20, please follow these instructions carefully:
  1. Is your current version older than JMRI 4.12? If so, then update to JMRI 4.12 first, and ensure everything works correctly: check start-up, check things you need to be working, and check the JMRI log as well) before doing anything else. Store your configuration and panel files under a new name and use those from now on. Then continue with step 2.

    If you are currently using JMRI 4.7.3 or earlier on Linux or macOS (Windows doesn't need this), then it's very important that you update to JMRI 4.12 and carrying out the migration process described in the JMRI 4.12 release note before updating to any later relese.

  2. Is your current version older than JMRI 4.20? Then update to JMRI 4.20 first, and ensure that works correctly (check start-up, check things you need to be working, and check the JMRI log as well) before doing anything else Store your configuration and panel files under a new name and use those from now on.
  3. You can then install this release.
Following this multi-step order of updating via stable major releases safeguards you against possible migration issues that can arise from skipping these versions.

Known problems with this release

New warnings for this production release:

Older warnings

See the JMRI 4.20 release note for more warnings predating the 4.21 development series. These may be relevant to you if you're updating from an earlier version.

Download links:

Please note that the download links in this and future JMRI releases link to Github servers. People are welcome to distribute the download files further via other websites, etc. If you want to check that you've received original, unmodified versions, please check the files against the checksums shown below.

Changes since production release 4.20:

This production version is made from test releases 4.21.1 through 4.21.5. The full list of changes in those is available from our code repository.

Hardware Support

Acela CTI

CBUS

C/MRI

DCC++

DCC-EX

DCC4pc

Public Domain and DIY decoders

ESU

Internal

IPOCSMR

LocoNet

Maple

MQTT

OpenLCB

Pi

RFID

SoundTraxx

SPROG DCC

TAMS

Uhlenbrock Intellibox

XPA

New / Updated decoder definitions

Digikeijs (Digirails)

Digitrax

ESU

Tam Valley Depot

Uhlenbrock

DecoderPro

CTC Tool

Control Panel Editor

Circuit Builder

Palette

Some minor changes are made to the user interface.

Dispatcher System

Internationalization

Layout Editor

Logix

Meters and MeterFrames

Operations

Preferences

Routes

Scripting

Signals

Signal Systems

Signal Masts

Cab Signals

Switchboard Editor

Throttle

Timetable

Turnouts, Lights, Sensors and other elements

Virtual Sound Decoder

Warrants

Web Server

Where Used

Miscellaneous