Release Notes for JMRI 4.15.1 release

Date: December 23, 2018

From: Bob Jacobsen

Subject: Test Release 4.15.1 of JMRI/DecoderPro is available for download.


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 first in a series of test releases. We expect this series to end in the next JMRI production release during early Summer 2019. (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.

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 JMRI 4.9.6 or earlier, we strongly recommend that you update to JMRI 4.12 and make sure that's running OK before updating to this test release. There have been a number of changes in serial port support, panel file format and configuration options since those earlier releases, and moving to the stable JMRI 4.12 release is a good way to work through any possible problems.

If you are currently using JMRI 4.7.3 or earlier on Linux or macOS (Windows doesn't need this), you must update to JMRI 4.12 and carrying out the migration process described in the JMRI 4.12 release note before updating to this release.

Known problems with this release

New warnings for this release:

Older warnings

See the JMRI 4.14 release note for more warnings predating the 4.15 development series. These may be relevant to you if you're updating from an earlier version.

Since JMRI 4.11.4 There are issues with the Pi-SPROG One command station operation. A number of workarounds should be applied:

Pi-SPROG One with version 2.4 or earlier firmware will cause a timeout after a track short circuit. A dialog box will open to inform the user of this. The track power will be turned off and must be turned on again using the power control.

Since JMRI 4.11.2 The system connection preferences (i.e. hardware preferences) are now enforcing the correct form for system prefixes: One upper case letter, optionally followed by a number (one or more digits, e.g. "L12"). Existing prefixes in existing configurations are unchanged, but new ones will have to have the correct form. If your layout uses a non-compliant prefix, i.e. "DX", "DCCPP", "DP", "MR", "MC", "PI", or "TM" please contact us for help in getting it migrated to a proper form. JMRI 4.16 will require that this have been fixed.

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 4.14:

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

Hardware Support


Roco z21/Z21

New / Updated decoder definitions





  • Added "Accept All" button to roster import
  • Dave Heap improved how the decoder identification process handles optional CVs

Layout Editor

  • Dave Sand improved tooltip handling


  • Added "Accept All" button to roster import operation
  • Improved handling of timestamps for the last run and running duration features


Signal Systems

  • Petr Šídlo updated the Czechoslovak state railway Elektrosignal Praga (CSD ESP) definition


since 4.13.4
  • Dave Sand made multiple updates to the Timetable support


  • Pete Cressman updated how Warrants interact

Web Access

  • Multiple updates to the JSON service


  • Fixed a compatibility problem when reading files containing timebase information