How To Fix WER194 - Expression &1 result parameter is not of type boolean

SAP Error Message - Details

• Message type: E = Error

• Message class: WER - Messages for the package WER

• Message number: 194

• Message text: Expression &1 result parameter is not of type boolean

Self-Explanatory Message

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Smart SAP Assistant

• What is the cause and solution for SAP error message WER194 - Expression &1 result parameter is not of type boolean ?

  The SAP error message:
  WER194: Expression &1 result parameter is not of type boolean
  
  Cause:
  This error occurs when an expression in a condition or a rule is expected to return a boolean value (true or false), but the actual result is of a different data type (e.g., integer, string, or any non-boolean type). The system enforces that conditions or expressions used in decision tables, BRF+ rules, or other logical constructs must evaluate to a boolean to determine the flow or decision correctly.
  For example, in BRF+ (Business Rule Framework plus), if you define a rule or expression that is supposed to return a boolean but the expression returns a number or string, this error will be raised.
  
  Solution:
  
  
  Check the Expression Return Type:
  
  Review the expression or rule referenced in the error message.
  Ensure that the expression returns a boolean value (true or false).
  If the expression currently returns a numeric or string value, modify it to return a boolean.
  
  
  
  Modify the Expression Logic:
  
  If the expression returns a numeric value, convert it to boolean by comparing it to a value, e.g.:
  (some_number > 0)  " returns boolean true or false
  
  If the expression returns a string, compare it to a string literal:
  (some_string = 'X')  " returns boolean true or false
  
  
  
  
  Check the Data Types in BRF+ or Decision Table:
  
  In BRF+, verify the data object types and ensure the output parameter of the expression is defined as boolean.
  Adjust the expression or the output parameter type accordingly.
  
  
  
  Debugging:
  
  Use the ABAP debugger or BRF+ trace to identify the exact expression causing the issue.
  Check the data types of all intermediate results.
  
  
  
  
  Related Information:
  
  
  Where it commonly occurs:
  
  BRF+ rules and expressions.
  Condition expressions in workflows or decision tables.
  Custom ABAP code where boolean expressions are expected.
  
  
  
  SAP Notes and Documentation:
  
  Check SAP Help Portal for BRF+ expression types.
  SAP Notes related to BRF+ expression errors.
  SAP Community forums often discuss similar issues with boolean expressions.
  
  
  
  Example:
  Suppose you have a BRF+ expression that returns an integer 1 or 0 to indicate true or false. This will cause WER194 because the return type is integer, not boolean. Instead, change the expression to:
  (integer_value = 1)
  which returns a boolean.
  
  
  
  If you provide the exact context or the expression causing the error, I can help you with a more specific fix.