Release Notes for JMRI 5.15.6 release
Date: April 9, 2026
From: Bob Jacobsen
Subject: Test Release 5.15.6 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)
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:
- 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.
- 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.
- 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.
- 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.
- 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
New warnings for this release:
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.
- Since JMRI 5.15.1
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.
- Since JMRI 5.15.4
The way mouse clicks are handled has been updated.
Although this has been tested with mice and trackpads,
it's possible that this will cause problems with other hardware,
e.g. touch panels. If you do encounter new problems with clicking
on panels, please contact us on the
JMRI users list.
- span class="since">Since JMRI 5.15.4
The RailCom handling has been updated to current standards. In particular, the enum
representing the orientation has been changed from ORIENTA and ORIENTB to
EAST and WEST respectively and some of the text strings have changed.
These may affect any scripts you have that reference
the direction of a RailCom report (tag) or parse the status messages.
- span class="since">Since JMRI 5.15.5
The web server folder app has been removed. It
might cause third party applications to fail. If this happens to
you, please contact us on
the JMRI users group.
Download links:
These files are located in the
JMRI 5.15.6 GitHub release.
The
full list of included changes is available from our
GitHub code repository.
Hardware Support
MERG
- Fixed a problem introduced in 5.15.4 where some RFID messages
would be improperly decoded as RailCom reports.
- Improved how special characters in filenames are
handled by the ChangeDefaultBackupFileName.py script
- Updated the OpenLCB_Java library to include an
improvement in how unknown-MTI messages are displayed.
- The event-entry field on the Send Frame panel will now
allow entry of event names.
- The popup menu on event entry fields now lets you copy
the numerical event ID even if a event name has been entered.
New / Updated decoder definitions
Piko decoders
- New: Piko Decoder Scale G support, more LC controller types definition
Changes: product-ID identification, new decoder firmware version, new CVs
Bug fixes and various improvements
Update Decoder Definitions is highly recommended
SoundTraxx
- New file TSU2 OEM Athearn N
ZIMO
- Improved how some recent Zimo decoder types are detected.
DecoderPro
- Added an option in the settings Roster pane, Programmer tab,
to drop detachable tabs for the programming panes.
- When you have a roster entry open for editing,
there are new entries in the File menu Import
and Export submenus to export
"All Function Labels to CSV file..."
and import a
"CSV file of Function Labels...".
They do what you'd expect.
- New permissions selection to allow/disallow adding/editing/removing
columns from the roster
Internationalization
- Various work in several languages
Layout Editor
- You can now add an "Output Indicator" to a
Layout Editor panel. This shows the status of a JMRI Turnout object.
Note that this is not a layout turnout; you can't
connect track to it or use it for signaling.
Rather, it's a way to represent a power switch, accessory
or other non-track thing that's driven by a JMRI output using
a Turnout object.
LogixNG
- Add Section and Transit to the bean listeners.
OperationsPro
- The Yardmaster's window now allows you to add cars to the train at the yardmaster's location.
- Fixed the departure time from a route location in the CSV Manifest file.
PanelPro
- Added a "Tables Settings" item to the Tables menu to allow the adding of the Tables menu to the Main Menu.
Roster
- Fixed a problem preventing the JMRI permissions from
properly controlling access to added columns.
Virtual Sound Decoder
- Added LayoutEditor Traverser support for VSD navigation through a panel.
