NullPointerException in Process Instance Query

Description

The error occurs when some process instances (of the very same process) are executed simultaniously (about 10) and at the same time my REST service queries those instances including their variables:
{{for (final ProcessInstance pi : this.runtimeService.createProcessInstanceQuery().includeProcessVariables().processDefinitionId(definitionId).list()) {
...;
}}}

Environment

Windows 7, Karaf 3.0.3, Activiti 5.17 running as OSGi bundle

Status

Assignee

Joram Barrez

Reporter

Hans-Peter Werner

Labels

None

Components

Affects versions

5.18
Later
5.17

Priority

High
Configure