Troubleshooting Eclipse StatET RMI Registry Port Errors on Windows

How to resolve the RMI registry port error ‘RMI Registry at port 51199 could not be started’ in Eclipse with StatET on Windows.
engineering
R
Eclipse
StatET
Author

Friedrich Pahlke

Published

June 17, 2025

Introduction

I have been an enthusiastic StatET user since 2018, and whenever I install a new version of Eclipse, StatET, or R on Windows, there are always a few small technical hurdles to overcome. Last year — and again today — I ran into the familiar “RMI Registry port” error when launching R under StatET. I’m taking this opportunity to share the solution I found, so others can save time when they encounter the same issue.

Background: StatET 4.11.0 and Recent Changes

Recently, Stephan (the StatET maintainer) announced StatET 4.11.0. Highlights include support for R 4.5 and ANSI escape sequences in the R console, among other minor improvements. Below is an excerpt of his message, with links inserted at appropriate points:

Dear StatET users,

I am pleased to announce StatET 4.11.0, a new version of the Eclipse-based IDE for the R language.
StatET 4.11.0 Release Announcement

This release provides support for R 4.5, support for ANSI escape sequences in the R console, as well as several other minor improvements. Details of these and more noteworthy changes are presented here:
Noteworthy Changes in StatET 4.11

The new version is available for Eclipse IDE 2025-06:
Eclipse IDE 2025-06 Download.
StatET 4.11 officially supports R 4.3 – 4.5, but other versions of R may work too.

To install the new version, you can use the following update site:
https://download.eclipse.org/statet/releases/4.11/E202409

For other download options, please check the download page:
StatET 4.11 Downloads

If you want to use the advanced console (RJ) with R, you need the R package rj for your R version as before. The packages for GNU R (RJSrv4GR) are not part of the Eclipse StatET project; for installation see the instructions at the project site:
RJ Server Installation Instructions
The R packages with version numbers 4.0.x (for RJ 4.0) are also compatible with StatET 4.11. I recommend updating to the latest release 4.0.11 if you have not done so yet.

Thanks to everyone who has contributed to this release.

Regards,
Stephan

With these updates in mind, you may upgrade to StatET 4.11.0 on Eclipse 2025-06 and R 4.3–4.5 (or your preferred R version), but you may still encounter the RMI registry port conflict when launching R via StatET, especially on Windows.

The RMI Registry Port Error

When you start Eclipse (with StatET installed) and launch an R session, you may see a dialog like this:

Port Error Screenshot

Error:
‘Launching R 4.3.1’ has encountered a problem.
RMI Registry at port 51199 could not be started. The new process terminated
with exit value 1.
commandLine=“C:...
jre” 51199
-J-Djava.rmi.server.codebase=file://…
-J-Djava.rmi.server.hostname=127.0.0.1

Typically, this means that the default RMI Registry port (often 51199) is already in use on your machine, or the port range is too narrow. StatET’s RJ console tries to start an RMI registry on a port in a small default range, and if all ports in that range are occupied, you get this error.

Solution: Expanding the RMI Port Range

The workaround is to configure StatET to use a wider port range for the RMI registry. You can do this via the StatET advanced configuration. Specifically, add or modify the property:

org.eclipse.statet.jcommons.rmi.registry.TcpPort=51100-51299

This expands the default port range from 51100–51199 to 51100–51299, giving StatET more options to bind the RMI registry.

Step-by-Step: Adjusting the Port Range

  1. Identify the StatET Config Location

    • Depending on your Eclipse installation, StatET stores settings in your workspace or in the Eclipse installation’s plugin configuration. Consult:
      StatET Advanced Configuration
      for your specific version.

    • Open the config.ini in the folder C:\Users\[my_user_name]\.eclipse\org.eclipse.platform_[my_eclipse_version]_win32_win32_x86_64\configuration.

      Example - your config.ini may look like this:

      # This configuration file was written by: 
# org.eclipse.equinox.internal.frameworkadmin.equinox.EquinoxFwConfigFileParser
# Fri Nov 22 14:59:28 CET 2024
eclipse.p2.data.area=@config.dir/../p2/
osgi.sharedConfiguration.area=file\:configuration/
  2. Add or Edit the Property
    • Add the line:
      org.eclipse.statet.jcommons.rmi.registry.TcpPort=51100-51299
    • If multiple key-value pairs are present, ensure each is on its own line, and do not include confidential local paths.
  3. Restart Eclipse
    • After saving configuration edits, restart Eclipse to apply the new port settings.
  4. Launch R via StatET
    • Try launching R again. If the previous conflict was due to the narrow port range, StatET should now successfully start the RMI registry on a free port within 51100–51299.

Troubleshooting Further

  • If you still see a port conflict, you can further expand the range, e.g., `51100-52000`. However, a very large range may be unnecessary; choose a small range that avoids conflicts on your system.
  • Ensure no firewall or security software blocks RMI registry ports.
  • Verify that your R version is compatible with StatET 4.11.0 (R 4.3–4.5 officially supported). If you use a different R version, you may need a compatible rj package:

Conclusion

Encountering the RMI registry port error can be frustrating, but expanding the default port range in StatET’s configuration is usually enough to fix it. By following the steps above—adding org.eclipse.statet.jcommons.rmi.registry.TcpPort=51100-51299 (or a suitable range) — you should be able to launch R sessions without the “port 51199 could not be started” error.

Happy coding with StatET and R on Windows! Feel free to leave feedback or share other tips for avoiding port conflicts.