DROID not opening on MacOS 15.6.1 (UnsupportedClassVersionError)

[Alexander Waterman]

Good morning!

I've started a new job and I'm still getting software set up on this system and I've run into an issue opening the "droid.sh" file with Terminal on my computer. I have a MacBookPro (2024 M4) and it is running Sequoia 15.6.1.  I have tried re-installing DROID, I've run chmod commands, checked permissions, and walked through some of the usual culprits in terms of permissions on Macs. What I'm seeing is that DROID begins to open and hangs on the loading window in the GUI and in Terminal it gets to this line: "at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)" and then hangs. 

I am seeing that there is an "Exception in thread" that looks like a JavaRunTime error. I have the latest Java installed on this computer (I also checked that) but it says that the application was created with a more recent version of the Java Runtime (class file version 61.0) and that the version I am running can only recognize file versions up to 52.0.  

Is this the issue? Does anyone know how I can resolve this? Should I try to find an earlier version of DROID? 

Thank you so much for any leads or help you can provide! 

Alex Waterman

Music & Audiovisual Archivist

World Music Archives

Wesleyan University

860-685-2302

awat...@wesleyan.edu

[Ross Spencer]

It looks like a user interface issue so the problem might be with the version of the Java AWT libraries installed. 

Do you have the specific java version string with `java -version`? 

A common gotcha can be Oracle's Java versioning versus Java.com -- you need the latest from here: https://www.oracle.com/java/technologies/downloads/ not https://www.java.com/en/download/manual.jsp 

Another potential issue could be official Java versus a variant like OpenJDK -- although I think these issues are less likely these days.

Best,

Ross

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[Tyler Thorsted]

Alexander,

Yes, as Ross mentioned it is probably a Java version issue. I am on Sonoma, Macbook Pro M1 and my Java version is: "openjdk version "21.0.8" 2025-07-15".

Also, what DROID version are you trying to run? DROID 6.8.0 and below are best under java 21 and 6.8.1 and above prefer java 21. You can get the latest from here.

https://github.com/digital-preservation/droid/releases/

Tyler Thorsted

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[Alexander Waterman]

Thanks Ross! 

my java -version is: 

java version "1.8.0_471"

Java(TM) SE Runtime Environment (build 1.8.0_471-b09)

Java HotSpot(TM) 64-Bit Server VM (build 25.471-b09, mixed mode)

I am going to try downloading the latest from Oracle as you mentioned and see if that gets me further.. I will report back. 

A

[Tyler Thorsted]

Alexander,

I would recommend on a Mac to use homebrew to install openjdk. brew install openjdk@21

[Alexander Waterman]

Thank you Tyler and Thank you Ross, 

I removed the version of Java I had and installed the latest jdk. 

That did it! 

I also updated to the latest build of DROID. Opens up. Going to do some further testing, but it seems to be up and running! 

Many thanks! 

Alex

[Ross Spencer]

Great stuff Alex, glad to hear you're up and running! 

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