Odd behaviour of JMRI on Ubuntu running on Raspberry Pi

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New Member
Recent issue on my JMRI installation.

It was working fine one day, programming locos and operating trains. next morning neither panel pro or decoder pro would open the comprehensive programmer for any loco on the roster.

This is running on a Raspberry Pi model 4B with 8Gb ram and from a 256Gb SSD attached to a USB 3 port. System software is Ubuntu Mate 20.4.

This system and JMRI (4.20) combination has been stable since set up about 6 months ago

The whole system, when operating satisfactorily, was backed up to another 256Gb USB stick for recovery if required.

On failure of the panel pro and decoder pro to operate properly I checked the DCC++EX command station and even reloaded the software - no change. I then fitted the back up system - and experienced EXACTLY the same failure mode with a system and software setup which had been working perfectly 6 months prior.

At this point I downloaded the latest version of JMRI and did a complete reinstall, importing my loco roster from storage.

All fixed, no further issue!

Glad to be operational again, but concerned that two complete systems, one of which had not been used since storing failed for no apparent reason. It raises questions like Linux that reliable? No system changes have been made in the interim. Is there something amiss with the version of JMRI I was running prior to failure was V4.20. currently have 4.24 installed.

Can anyone come up with an explanation for this strange behaviour?


Active Member
Linux is super reliable. But that doesn't guarantee that apps written for it are. It's probably an obscure bug in JMRI. It would be completely impossible to find the cause given only this information. It could even be a problem with the Java run time module.

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