The Essential Project Forum

Posted: **19 May 2024, 22:12**

Hello,

Today after my Windows PC reboot, I got attached pop up saying it's processing of "loading ontology changes", but it's not stopped, and nothing response either "Hide" or "Cancel".

There's error message shown in the protege terminal:

Code: Select all

java.lang.NullPointerException
        at edu.stanford.bmir.protegex.chao.change.api.ChangeFactory.getAllComposite_ChangeObjects(Unknown Source)
        at edu.stanford.smi.protegex.changeanalysis.util.DataFacade.initDataCollections(Unknown Source)
        at edu.stanford.smi.protegex.changeanalysis.util.DataFacade.<init>(Unknown Source)
        at edu.stanford.smi.protegex.changeanalysis.util.DataFacade.getInstance(Unknown Source)
        at edu.stanford.smi.protegex.changeanalysis.ChangeAnalysisTab$2.run(Unknown Source)
        at java.lang.Thread.run(Thread.java:750)
Started Collaborative Protege on Sun May 19 16:07:34 EDT 2024

If I close the terminal, the Protege is closed, so now I cannot enter my project.

Before I have to load my latest backup, which means I'll lose one full week's work, is there any hint to help me fix this error?

Thanks greatly,
Xiaoqi

Posted: **22 May 2024, 14:10**

Hi,

This is unusual error.

Did you recently make any configuration changes, e.g., enabling Collaboration features?

Have you been running the Collaboration features?

Can you confirm you are using Java 8 with this installation?

Are you seeing any related database errors?

Let me know,

Neil

Posted: **30 May 2024, 14:31**

Hi Neil,

Sorry for not replying in-time, I have some urgent modeling so I had to restored to one earlier backup and redo the work in the past days instead troubleshooting.

Now got time to check this, yes, even I use in standalone Protege, I had activated the "ChangeAnalysis" tab to record the change log.

Here is my java version:

Code: Select all

openjdk 11.0.16.1 2022-08-12 LTS
OpenJDK Runtime Environment Microsoft-40648 (build 11.0.16.1+1-LTS)
OpenJDK 64-Bit Server VM Microsoft-40648 (build 11.0.16.1+1-LTS, mixed mode)

When it happens, it's just freezing in frontend so nothing can click, and I don't have backend database for this now.

Thanks a lot,
Xiaoqi

Posted: **30 May 2024, 14:42**

Hi,

As mentioned on our download page, Essential only supports Java 8 and will likely cause issues such as the ones shown with any other version. You have Java 11 installed. Can you try installing Java 8 and see if the issues resolve themselves.

Thanks

Neil

Posted: **31 May 2024, 11:29**

Thanks Neil, I'll try to configure to downgrade Java to 8 and observe this.

The Essential Project Forum

[Help] Model opening error saying "Loading ontology changes..."

[Help] Model opening error saying "Loading ontology changes..."

Re: [Help] Model opening error saying "Loading ontology changes..."

Re: [Help] Model opening error saying "Loading ontology changes..."

Re: [Help] Model opening error saying "Loading ontology changes..."

Re: [Help] Model opening error saying "Loading ontology changes..."