Nope. That didn’t work.
I saved ALL my rules again as I cannot figure out what rules are referenced by the error. It would be nice to find the offending rule.
Anyway like you said worth a try.
I have the same problem. I have version 5.1.0. I saved all my rules again, cleared the cache, removed the JavaScript Scripting binding, and reinstalled it, but the error still occurs when starting up.
2025-08-20 11:43:53.443 \[ERROR\] \[ipt.internal.ScriptEngineManagerImpl\] - ScriptEngine for language ‘application/javascript’ could not be found for identifier: 6a860b00-4e61-44dc-9a31-855b1fc1a834
2025-08-20 11:43:53.451 \[ERROR\] \[ipt.internal.ScriptEngineManagerImpl\] - ScriptEngine for language ‘application/javascript’ could not be found for identifier: a9f9aff2-c6da-483f-b1eb-1bb9a777ff86
2025-08-20 11:43:53.456 \[ERROR\] \[ipt.internal.ScriptEngineManagerImpl\] - ScriptEngine for language ‘application/javascript’ could not be found for identifier: 4858a91e-1fdb-4a31-938a-2aa04e8540b6
2025
I have the same problem with the newest version 5.0.1. All rules are file based but seem to work.
After a stop of Openhab and reboot four hours after the upgrade there are no more error messages.
Everything works.
The messages only appear when starting.
It could be useful if that error log provided a meaningful identifier that the users could easily use to identify the rule that is failing. But it’s not really needed here. Essentially any rule that triggers while the JS Scripting add-on is not yet available will generate this error.
This can point to a loading/timing issue. The JS Scripting add-on is not yet available when start level 40 is reached and rules start triggering. Eventually it does get loaded and the error messages stop.
I just upgraded to 5.0.1 and I too saw these error logs. But I always see error logs like these after an upgrade or clearing of the cache. It simply takes too much time to download and install the bundles and therefore when OH reaches later start levels (40+) the add-ons are not available when OH starts processing events and running rules and such.
Usually, after waiting for everything to settle and restarting OH all these sorts of errors go away. However, I’m now seeing these error messages too.
The key thing is these logs happen long before the system reaches start level 40 which is when the rules engine is started. Of course the add-on isn’t available yet at that point.
I see these messages appear about 17 seconds into the boot process but start level 40 isn’t reached until nearly a minute into the startup process (on my system, your times will be different).
Something changed that causes ScriptEngineManagerImpl to be invoked (loading the files from JSONDB?) really early in the OH startup process, much too early for the add-on to be available. I suspect if you counted up the errors it would be the number of Script Actions and Script Conditions you have defined.
The good news is these error messages are not really of concern. No rules are executing at this point. They can’t, the rule engine hasn’t started yet. It’s clearly not stopping the rules from running eventually.
tl;dr: It’s definitely a problem that needs to be addressed but there is no impact to OH running correctly. These error messages are themselves in error and there is no problem.
Note, this analysis only applies for those who are seeing these messages during startup but once start level 40 is reached the rules run correctly as expected.
I created an issue: ScriptEngineManagerImpl invoked too early in the startup process · Issue #4965 · openhab/openhab-core · GitHub
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Sorry about the late feedback…
I have just installed the latest SNAPSHOT - error is gone.
So thanks to all you assisted.