Error NoClassDefFoundError

Hallo,

I try to start my process in Tasklist, but it will not work. I click on “Start Process” and the window open with the start Process Titel, but than just the loading animation runs. The Console shows "Failed to load resource: the … ", “server responded with a status of 500 ()”. “type”: “NoClassDefFoundError”,
“message”: “Could not initialize class org.camunda.bpm.model.bpmn.Bpmn”

Can someone help me?

Hi @fkeolix
Welcome to the forum.

Please provide some additional information on your issue. Usually, some useful things to provide are:

  1. Application server, database, JDK version, etc;
  2. Process engine configuration;
  3. The problematic BPM process;
  4. Steps to reproduce the issue or example project.
  5. Any logs/stack traces that are shown when the process is started.

Open Source Community Edition

operating system: macOS Catalina

Browser: Safari

Distribution Type: Camunda Platform Run

JAVA Version: 8

  1. Process engine configuration: Where can I read the Process engine configuration?

  2. Process: diagram_1.bpmn (2.4 KB)

  3. Deploy the diagram_1, open tasklist, click “start process”, get Error

  4. Error: Error.pdf (19.0 KB)

Hi @fkeolix
Thanks for all the information.

I tried out that model myself and i was able to deploy it and start is without any problems… So something else must be going on.
Can you check the console on Camunda Run to see if there are any errors?

Logs:
Logs.pdf (50.7 KB)

We just had the same error in our study group, one member saw this error on Windows. We observed the same NoClasDefFoundError in the Chrome Developer tools.

Upon debugging, there was a series of other exceptions in the logs. In this case the root cause was, that the JAR was in a synchronized OneDrive folder and the engine was not able to read the XSD Schema for the bpmn files from the JAR (I’m not sure how it lead to a NoClassDefFoundError). After moving the JAR to a different location, everything worked just fine.

Can you please upload the full logs from your Camunda instance? The pdf only contains two lines for me, which are not really expressive.

2 Likes

I work with docker that’s works for me now. Thanks for your answer.