### Answer This error occurs when dynamic variables aren't formatted correctly. Dynamic variables must use the exact format

{{variable_name}}

with double curly braces on both sides. [(1) ]() Common issues that trigger this error: - **Missing or extra braces**: Using

{variable_name}

or

{{{variable_name}}}

instead of

{{variable_name}}

- **Spaces inside braces**: The spaces around the variable name will be trimmed when evaluating, but ensure you're using the correct syntax - **Invalid characters**: Variable names should follow standard naming conventions **Tip**: Many supported fields include a variable picker to help avoid formatting errors. Type

{{

where you want a variable, and a dropdown will appear listing available variables. You can filter by typing more characters, then select with Enter, click, or Tab. Make sure your variables follow the

{{variable_name}}

format exactly, and the error should resolve.

​ To learn more, see the sources I considered: [[1] Dynamic Variables](https://docs.retellai.com/build/dynamic-variables) ​

Feel free to tag @AI Evy with additional questions. I also appreciate feedback, it helps me improve.