Release Notes for JMRI 5.17.5 release

Date: MM DD, 2026

From: Release Pumpkin

Subject: Test Release 5.17.5 of JMRI/DecoderPro is available for download.

This is a draft release note only; the download links do not yet work

Notes:

This is a test release. Please post a note if you encounter any new or old bugs! And please back up your JMRI files before installing this, in case you want to go back to an earlier version.

This is the next in a series of 5.17.* test releases. It requires at least Java 11 to work. We recommend that you use Java 21 if possible. (See our page on downloading Java) We expect this series to result in the next JMRI production release in December 2026. (See the tentative release schedule)

Some of the changes involved are quite extensive. They may require a certain amount of experience before they are working well. Therefore, this test release should be considered experimental. We would appreciate your feedback on it.

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 5.0, 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 release.

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. Save your preferences again. Store your configuration and panel files under a new name, use those from now on, and go on to step 3.
3. Is your current version older than JMRI 4.24? Then update to JMRI 4.24 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. Save your preferences again. Store your configuration and panel files under a new name and use those from now on.
4. Is your current version older than JMRI 5.0? Then update to JMRI 5.0 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. Save your preferences again. Store your configuration and panel files under a new name and use those from now on.
5. 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.

New problems with this release

• None yet

New warnings for this release:

Older warnings

See the JMRI 5.16 release note for more warnings predating the 5.17 development series, including pointers to various migration issues. These may be relevant to you if you're updating from an earlier version; we strongly recommend you update to at least JMRI 5.0 before installing this test release. See instructions above.

• Since JMRI 4.99.1 If you're using a Firefox web browser and opening JMRI help files locally (not over the web), a Firefox bug can sometimes cause it to enter a loop. There's a workaround in this JMRIusers post.

Download links:

During development leading to the actual release, you can find test download files on the continuous integration build page. These are development files, and might not be working at any particular time.

Changes since Test Release 5.17.4:

The full list of included changes is available from our GitHub code repository.

Hardware Support

Acela CTI

Anyma DMX512

Bachrus Speedo

BiDiB

CBUS

• CBUS performance on busy layouts: incoming frames are dispatched to sensors, turnouts and lights with much less work and no per-frame garbage, and the Event Table and Console do far less work for each frame.
• The CBUS fast clock uses the calendar year rather than the week-based year, accepts and sends temperatures from -128 to 127 correctly, and stops listening to the JMRI clock when it is disposed. CBUS consist listeners are no longer shared between connections.
• CBUS throttles: a released throttle is removed from the session list, so an emergency stop reaches every remaining throttle instead of failing partway through; after a command station reset a recovered session is only given back to the throttle for the same loco; and nothing is sent to the layout while a throttle has no session, where previously a speed or function change could go out with an invalid session.
• The CBUS bootloader checks a hex file before it can be used. The Program button stays disabled until the file has been read without error and its parameters checked; a file with record types the bootloader does not understand is rejected; the MERG parameter block checksum is now verified; and a load address missing from the file stops programming cleanly instead of throwing an exception. The hex file is closed after reading instead of being left open and locked, and short records are padded correctly for the AN247 bootloader.

C/MRI

DCC++ and DCC-EX

DCC4pc

Direct

ESU

Hornby

Internal

IPOCSMR

JMRI Simple Server/JMRI Client

KPF-Zeller

Lenz XPressNet

LocoNet

Maple

Marklin CS2

MERG

MQTT

MRC

NCE

Oak Tree

OpenLCB / LCC

• Added a dialog to draw attention to the error if a firmware update fails.

Powerline

RFID

Raspberry PI

Roco z21/Z21

Secsi

SPROG

SRCP

TAMS

TMCC

Uhlenbrock Intellibox

Zimo

ZTC

New / Updated decoder definitions

AE Model

Arnold

Bachmann

BLI

BNM Hobbies

CT Elektronik

DCC Concepts

Digikeijs (Digirails)

Digitrax

Doehler & Haas

ESU

Hattoms

Hornby

Kuehn

LaisDCC

LDH

Lenz

MD Electronics

MGP

Mistral Train Models

MTH

MRC

NCE

Norsk Modelljernbane (NJM)

Piko decoders

Public Domain and DIY decoders

QSI

Rampino Elektronic

Rautenhaus

RR-CirKits

SoundTraxx

Tam Valley Depot

TAMS

TCS

Team Digital

Technologistic (train-O-matic)

Trix Modelleisenbahn

Uhlenbrock

Umelec

Viessmann

Wangrow

ZIMO

Miscellaneous

Control Panel Editor

Circuit Builder

Palette

CTC Tool

DecoderPro

Dispatcher

• When the maximum speed of an automatically running train is entered as a scale speed (scale mph or scale km/h), that limit is now applied as entered. Previously it could be reduced by the stored throttle percentage value in the Physics ramp and in distance-based stopping. The throttle percentage is now only a fallback for locomotives without a speed profile, or when the profile does not cover the direction of travel; a warning is written to the system console in that case.
• The scale speed conversions for the maximum speed and the scale speed shown for the minimum throttle now follow the "Run in reverse" setting, and the scale km/h entry is no longer labelled as scale mph.

Dispatcher System

Internationalization

Layout Editor

NX - Entry/Exit Tool

LccPro

Logix

LogixNG

Meters and MeterFrames

OperationsPro

• The program will now allow you to swap the same locomotives on a turn when using quick service.
• Improvements to YardMasterByTrack tool to display tracks with "similar" names together.
• Conductor and Yardmaster now have "Show Cars" in their tool menu.
• Conductor tool menu now has the YardmasterByTrack tool.
• Additional help for the new "On Time" mode of operations.

Panel Editor

Permissions

Preferences

Resources

Roster

Routes

Scripting

Signals

Signal Systems

Signal Heads

Signal Masts

Signal Groups

Cab Signals

Simple Signal Logic

USS CTC Logic

Switchboard Editor

Throttle

• JMRI Desktop Application Throttles now listen to Roster events, hence, if a roster entry is updated, the throttle will immediately reflect the changes
• Roster functions editor panel is now displayed as a table, the table can be reordered by dragging rows, which will change the order of the displayed functions buttons in the related JMRI throttle window (see #13700 ). Only implemented in JMRI Desktop Application Throttles for now, and no impact on keyboard shortcuts (1 or F1 is still F1, whatever the display order)

Timetable

Tracker

Turnouts, Lights, Sensors and other elements

Warrants

Web Access

Web Server

Where Used

WiThrottle Server

Virtual Sound Decoder

Z21 Server

Miscellaneous

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