DMN Boolean Error – Root Cause in Production (Real-World Analysis)
Introduction One of the most common and dangerous issues in DMN-based systems is a Boolean evaluation error in production . These errors often do not appear in local testing but suddenly break workflows after deployment. Typical symptoms include: DMN decision fails at runtime Process instance stuck or aborted Unexpected false decision output Runtime exceptions like: FEEL evaluation error Boolean expected but got null Cannot coerce value to Boolean This blog explains: What DMN Boolean errors are Why they happen in production Real root causes (from live systems) How to fix and prevent them What Is a DMN Boolean Error? In DMN, Boolean logic is used in: Input Expressions Decision Table conditions Literal Expressions FEEL expressions A Boolean error occurs when: DMN expects true or false But receives null , empty, wrong type, or invalid expression This leads to decision failure or wrong routing in BPMN processes...