History view of a multi-instance subprocess shows no tokens and a forever loading spinner

Environment:

Camunda Platform 7.17.0-ee

Description:

The history tokens are not shown for a completed multi-instance subprocess and a loading indicator that never ends is also visible.

Steps to Reproduce:

1. Deploy printer.bpmn as Printer
2. In Tasklist->Start a new process for Printer
3. Once the task has started go to Cockpit->Running Instances
4. Find your Printer process definition
5. Navigate to the completed process instance

Observed Behaviour:

No history tokens and a constantly loading spinner in the history view.

Expected Behaviour:

All history tokens should be displayed in the history view, and without a loading indicator present.

Root Cause:

With 7.17, we introduced the feature to drill down into embedded subprocesses. This changed the behaviour of the statistics badges that are generated on the process instance history diagram. The new logic iterates through all flow-nodes that are returned by the historic activity statistics request and maps it with the flow-nodes present in the BPMN XML model registry.

When viewing a process with a multi-instance subprocess, the multiInstanceBody is returned by the historic activity statistics request. However, this flow-node is an execution detail and therefore not part of the BPMN XML model registry. When trying to get the #businessObject of the non-existing multiInstanceBody, an error is thrown that leads to unexpected behaviour.

Solution Ideas:

Prevent further operations, such as annotating an element, if the activity is not present in the element registry.

Hints:

• The issue is isolated to the history view of the instance
• REST endpoints currently return the relevant historical data
• Check how the history token data is passed to the history view of the instance