Incident created for unable to load Delegate classes

Process engine created incidents for unable to load Delegate class with ‘Failed Job’ category. This is not happening for all transactions. but occasionally getting this incident of the same kind. Also, unable to reprocess this incident as this was created under ‘Failed Job’ category. Please advise anything wrong in the mapping of delegate class.


confo_validator.bpmn (8.1 KB)

Hi team, can anyone assist on this. Pls let me know if more details needed.

This issue occurs only if i select ‘async before’ option. Someone pls let me know whats wrong in the bpmn model.


Can you better describe your setup - it’s hard to answer the question without all the context.
Look at the style guide for more information about how to properly format your question.

Hi Niall,
Apologies for not specifying enough details.
Version- Camunda BPM 7.12
Setup - Spring Boot
Database - MariaDB (10.3)
no changes in the default configuration.

In the attached BPMN, added interrupted timer event for User task. and timer event calls Service task. when ever timer executes getting ‘Cannot load class’ exception and created an incident.

Attaching BPMN and Log for your reference.
error_trace.txt (12.1 KB) swap_validator.bpmn (7.9 KB)

How are you deploying the process? is it part of your Spring Boot project? e.g. in the resources folder?

Yes. Part of Springboot project, Placing bpmn files inside resources folder.

Are you using by any means spring boot developer tools in your project?

Can you copy the whole stacktrace here?

Hi Lucas,
We are not using springboot developer tools in this project. Enabled Camunda Stack trace, but unable to see any traces related to this incident. Attaching logs for your reference. Pls let me know any more details needed.

EDIT: I have removed the log file per author request.

Hi team, Pls let me know your suggestion on this issue.

Hi Team, Pls let me know if any findings.

Hi @Niall @lucas.silva

Version- Camunda BPM 7.12
Setup - Spring Boot
Database - MariaDB (10.3)
no changes in the default configuration

We faced same "delegate class not found " issue when we used ‘async before’ option in service task. we have 3 SpringBoot-Camunda apps running with one CamundaDB


We use ‘async before’ option in “SpringBoot-CamundaApp-1”. But, we get ‘delegate class not found’ exception in “SpringBoot-CamundaApp-2” logs. I am guessing, Camunda is looking to load delegate class from App2 instead of App-1. We are getting this error only if we use below options,

  1. Async before
  2. Async after
  3. User task - timer event

Pls assist on this issue, we are planning for rollover in another 2 months

@Prabhakar_Mariyappan all the three spring boot apps has same delegates?

Homogeneous or heterogeneous cluster setup?

Hi @aravindhrs, All three apps are independent apps having different set of delegate classes and deployed into Openshift.

@Prabhakar_Mariyappan I agree with that., since it’s heterogeneous architecture each process application will have it’s own or different delegates and processes. I hope you are using shared database.

Same schema or different schema?

If all the process applications shares same schema/table, then I would suggest you to enable the property deploymentAware=true

Yes. all apps are sharing same scheme.
Can you pls give full prop name/docs to refer for this ‘deploymentAware’.


@Prabhakar_Mariyappan, you need to set that property to process engine level configurations.

<process-engine name="default">
    <property name="jobExecutorDeploymentAware">true</property>

The process engine job executor is also clustered and runs on each node. The job executor can run in both homogeneous and heterogeneous clusters.

Read about the Job Execution in Heterogeneous Clusters and Configuration Properties

Property name Type Description
jobExecutorDeploymentAware Boolean Controls whether the job executor is deployment aware or not.
                                    Values:   `true` ,  `false`  (Boolean)

Thanks @aravindhrs.


Can i use this property to anable deployment-aware?

@Prabhakar_Mariyappan not able to view the image. can you re upload it?


Sorry for not uploading properly.