Release Notes for JMRI 5.15.1 release

Date: December 16, 2025

From: Bob Jacobsen

Subject: Test Release 5.15.1 of JMRI/DecoderPro is available for download.

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 5.15.* 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 July 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:

• The serial communications library that JMRI uses has been updated. If your JMRI installation is having trouble communicating with your model railroad hardware, please contact us on the JMRI users group.

Older warnings

See the JMRI 5.14 release note for more warnings predating the 5.15 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 This test release, and all subsequent ones, require the use of Java 11 or later. We recommend that you use Java 21. Java 8 is explicitly not supported. There's more information on this migration on the JMRI Tech Road Map and JVM Capabilities pages.
• 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:

These files are located in the CI project page. -->

Changes since Production Release 5.14:

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

Hardware Support

Digitrax

• Fix bug, PR4 Stand-alone Loconet

OpenLCB / LCC

• Fix STL Editor bug introduced in PR 14625.

New / Updated decoder definitions

Piko decoders

• Add scale G decoders, support new firmware versions

TAMS

• The LD-W-32.2 decoder has been added.

DecoderPro

• Fixed a problem causing the starting value when doing CV reads to erroneously be zero.
• When opening a roster entry with a large decoder definition, DecoderPro now defers some of the processing until later while opening the tabbed programming panes sooner. You may see a pane with "Wait for pane contents to be loaded". The contents should appear within a few seconds.

Dispatcher

• Defer calling "loadAtStartup" until the layout data file loading is done and layout block paths have been initialized.
• Create, terminate, open throttle, extend, terminate from LEPanel.

LogixNG

• Warning
  Tables and panels files created with this version or later and that's using the LogixNG action Error cannot be opened in earlier JMRI versions.
• The LogixNG action Error has an improved error message which allows using a local variable or a formula for the error message.
• LogixNG Tables can now be placed on Panel Editor panels. The table can be read-only, editable or that only some columns are editable. It's also possible to have buttons and comboboxes in the table on the panel.

Panel Editor

• LogixNG Tables can now be added to a Panel Editor. The table can be edited and that's is useful if the user needs to change values in a table.
  It's recommended to use Fixed size for the LogixNG Table on the panel. To move the table, use Set Location since it's not currently possible to move the table on the panel using the mouse.
  The width of the columns can be changed by dragging the divider of the column headers. The new width will be stored when the tables and panels file is stored.
  The table is not stored when the tables and panels file is stored.
  It's optional to use a LogixNG Module to validate input from the user. If a LogixNG Module is selected, it will be called after the user has edited a cell, before the new data is written to the cell. If the data is invalid, the Module can abort the editing by calling the new LogixNG action Validation Error in the category Flow Control. It's possible to add an error message to the Validation Error to be shown to the user.
  A LogixNG Table on a Panel Editor panel can also have buttons and comboboxes. If the user clicks on a button, the validation module can then do something. And a combobox allows the user to select an item from a list instead of typing it.

Scripting

• The TransitActionsReport.py has been added. It is used to display the transit section actions. When the script is run, a dialog displays the list of transits. If none are selected, a complete report is created.

Throttle

• Fixed a problem causing the Function Panel's buttons to be improperly laid out.

Web Server

• JSON Schema support has been upgraded from draft-04 to draft-2020-12, providing improved validation capabilities and modern schema features for JSON API responses. This includes updates to 95 JSON schema files and the underlying NetworkNT JSON Schema Validator library (from 1.0.28 to 1.3.3).

Miscellaneous

• (Developer) Updated build.xml so Ant builds work with Java 25
• (Developer) Updated SpotBugs checker to version 4.9.8. If you use Ant to do SpotBugs checks locally, i.e. by running "ant spotbugs-check", you will need to update your local version to 4.9.8. See our SpotBugs page.
• (Developer) JMRI distributions, starting with this one, will now be built with the Java 11.0.29 JDK.
• The jSerialComm library that JMRI uses has been updated from version 2.10.4 to version 2.11.4.

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