Medium severityconfiguration
Power BI Refresh Error:
DF-Executor-ExpressionParseError
What does this error mean?
An expression in a data flow transformation — a Derived Column, filter, join condition, or aggregate — contains a syntax error that the ADF expression engine cannot parse. The pipeline fails immediately at runtime before any data is processed.
Common causes
- 1A string literal in an expression uses double quotes instead of single quotes — ADF's expression language requires single-quoted string literals
- 2A parameter reference uses `@{pipeline().parameters.name}` syntax (ARM template style) instead of the data flow expression syntax `$paramName`
- 3An expression was edited directly in JSON or copied from another tool, introducing invisible characters or encoding issues that break parsing
- 4A function name is misspelled or used with the wrong number of arguments — ADF expression functions are case-sensitive
How to fix it
- 1Open the ADF data flow expression builder for the failing transformation and check for syntax errors — look for unclosed parentheses, mismatched quotes, or invalid function names.
- 2The error message names the line or expression that failed to parse; navigate directly to that Derived Column or filter expression.
- 3Validate each function call in the expression against the ADF expression language reference — function names are case-sensitive.
- 4If the expression includes pipeline parameters, verify the parameter syntax: use `$paramName` not `@paramName` in data flow expressions.
- 5Use the expression builder's 'Refresh' button to re-evaluate the expression and see the parse error highlighted in context.
Frequently asked questions
Official documentation: https://learn.microsoft.com/en-us/azure/data-factory/data-flow-troubleshoot-guide