Error while generating process diagram, image will not be…

Error message

Error while generating process diagram, image will not be stored in repository

What it means

During deployment, BpmnDeployer generates a PNG process diagram for each process definition when diagram generation is enabled. If any step of diagram generation throws, this warning is logged, the image is not stored as a deployment resource, and the deployment proceeds because the process remains executable.

Solutions

Add valid BPMNDiagram DI sections to the BPMN XML (re-save from the modeler)
Disable diagram generation: set createDiagramOnDeploy=false on ProcessEngineConfiguration
Check the configured labelFontName/annotationFontName are valid fonts available to the JVM

Example fix

// before
<property name="createDiagramOnDeploy" value="true"/>
// after (if DI cannot be fixed)
<property name="createDiagramOnDeploy" value="false"/>

Defensive patterns

Strategy: validation

Validate before calling

BpmnModel model = converter.convertToBpmnModel(...);
boolean hasDi = model.getLocationMap() != null && !model.getLocationMap().isEmpty();
if (!hasDi) config.setCreateDiagramOnDeploy(false);

Type guard

boolean hasDiagramInfo(BpmnModel m) { return m != null && m.getLocationMap() != null && !m.getLocationMap().isEmpty(); }

Try / catch

try { byte[] png = generator.generateDiagram(...); } catch (Throwable t) { LOGGER.warn("diagram skipped", t); }

Prevention

Export BPMN with DI information included
Validate font names configured on the engine exist in the deployment environment
Accept the warning as non-fatal; the process still deploys

When it happens

Trigger: createDiagram / ProcessDiagramGenerator throws (e.g. invalid or missing BPMN DI (diagram interchange) information, bad fonts, classloader issues) while isCreateDiagramOnDeploy is true.

Common situations: BPMN XML without BPMNDiagram/BPMNPlane DI sections; missing or incompatible fonts for configured label/annotation font names; corrupted models generated by tools.

Understand the failure class

Background: "failed to write file", "Could not save figure", "Error saving remote file" — file write failed: causes and fixes across languages and libraries — this error's family across 38 libraries.

Related errors

AI-assisted analysis of flowable/flowable-engine@d6d39ce1c6 (2026-09-11). Data as JSON: /api/errors/bad9f54f031951b7. Report an issue: GitHub.

Appendix: source

Thrown at modules/flowable5-engine/src/main/java/org/activiti/engine/impl/bpmn/deployer/BpmnDeployer.java:165

                    String diagramResourceName = getDiagramResourceForProcess(resourceName, processDefinition.getKey(), resources);

                    // Only generate the resource when deployment is new to prevent modification of deployment resources
                    // after the process-definition is actually deployed. Also to prevent resource-generation failure every
                    // time the process definition is added to the deployment-cache when diagram-generation has failed the first time.
                    if (deployment.isNew()) {
                        if (processEngineConfiguration.isCreateDiagramOnDeploy() &&
                                diagramResourceName == null && processDefinition.isGraphicalNotationDefined()) {

                            try {
                                byte[] diagramBytes = IoUtil.readInputStream(processEngineConfiguration.getProcessDiagramGenerator().generateDiagram(bpmnParse.getBpmnModel(), "png", processEngineConfiguration.getActivityFontName(),
                                        processEngineConfiguration.getLabelFontName(), processEngineConfiguration.getAnnotationFontName(),
                                        processEngineConfiguration.getClassLoader(),processEngineConfiguration.isDrawSequenceFlowNameWithNoLabelDI()), null);
                                diagramResourceName = getProcessImageResourceName(resourceName, processDefinition.getKey(), "png");
                                createResource(diagramResourceName, diagramBytes, deployment);

                            } catch (Throwable t) { // if anything goes wrong, we don't store the image (the process will still be executable).
                                LOGGER.warn("Error while generating process diagram, image will not be stored in repository", t);
                            }
                        }
                    }

                    processDefinition.setDiagramResourceName(diagramResourceName);
                    processDefinition.setEngineVersion("v5");
                    processDefinitions.add(processDefinition);
                    bpmnModelMap.put(processDefinition.getKey(), bpmnParse.getBpmnModel());
                }
            }
        }

        // check if there are process definitions with the same process key to prevent database unique index violation
        List<String> keyList = new ArrayList<>();
        for (ProcessDefinitionEntity processDefinition : processDefinitions) {
            if (keyList.contains(processDefinition.getKey())) {
                throw new ActivitiException("The deployment contains process definitions with the same key '" + processDefinition.getKey() + "' (process id attribute), this is not allowed");
            }

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