Description of problem:
backport of https://issues.jboss.org/browse/JBPM-3626
to be able to use conditional event to reason over only variables of a selected process instance name of the variable must be exactly 'processInstance'
any variable name should work as long as it is of WorkflowProcessInstance type
backported into 5.2.x branch
Verified in BRMS 5.3.1 ER1.
doc text has been edited for inclusion in the release notes. Thanks for providing the text, Maciej.