# 21656: The ContentVariables Parameter is invalid

Log Type: APPLICATION

Log Level: ERROR

## Description

The ContentVariables Parameter is invalid.

### Possible causes

* The ContentVariables Parameter is not a JSON String.
* A ContentVariables variable placeholder is improperly formed e.g. \{\{example}.
* A ContentVariables variable placeholder is an "empty mustache" e.g. \{\{}}.
* The ContentVariables field is defined with improper formatting at time of send.
* The ContentVariables field contains a variable that was set to null or empty string at time of send.
* Variables in body cannot contain newlines, tabs, or more than 4 consecutive spaces

### Possible solutions

* Review the [documentation](/docs/content/using-variables-with-content-api) on how to use Content Variables with Content Templates.
* Validate the ContentVariables Parameter, it must be a JSON String and be properly formatted.
* Make sure all ContentVariables are defined and have a valid definition at time of send. ContentVariables cannot be an empty string or null.