Missing parameter – A required parameter is missing from an action or trigger.

The “Missing parameter” error in Power Automate occurs when an action or trigger is expecting a required input, but it is empty or incorrectly formatted. This can prevent the flow from running successfully.

Common causes include:
✅ Required fields left empty in actions like SharePoint, Dataverse, or API calls.
✅ Dynamic content missing (e.g., an action before failed to return expected data).
✅ Incorrect expressions or variable assignments leading to null values.
✅ API requests missing key parameters (e.g., authentication tokens, IDs).

This guide provides step-by-step solutions to fix and prevent this issue.

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Step 1: Identify the Missing Parameter

1. Go to Power Automate → My Flows.
2. Click on the failed flow and open Run History.
3. Find the failed action and expand it.
4. Look for an error message like:
   • "Missing required parameter: XYZ"
   • "The input parameter cannot be null"
   • "A value must be provided for field: ABC"

Example

A SharePoint “Create Item” action fails because the “Title” field is empty, which is required.

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Step 2: Fix Missing or Empty Inputs

1. Check If Required Fields Are Empty

• Open the failing action and verify all required fields are filled.
• Ensure dynamic content fields actually contain values.

Solution

✅ Use Default Values to avoid null inputs:

if(empty(triggerOutputs()?['body/Title']), 'No Title', triggerOutputs()?['body/Title'])

✅ Use Conditions to handle missing data before passing it to the action.
✅ Add a Validation Step before executing actions that depend on input values.

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2. Verify That Dynamic Content Exists

Sometimes, an earlier action fails to return expected data, leading to missing parameters.

Solution

✅ Enable “Peek Code” (in action settings) to check the real JSON output.
✅ Use a Condition Action to verify if a value exists before using it.
✅ Use coalesce() to provide a fallback value:

coalesce(outputs('Get_Data')?['body/value'], 'Default Value')

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3. Check for API Call Issues (HTTP, Dataverse, SQL, etc.)

When calling an API or external service, ensure all required parameters are provided.

Solution

✅ Review the API documentation for required fields.
✅ Ensure authentication tokens are included in HTTP headers.
✅ If using JSON input, confirm that all required keys are present.

Example of a correctly formatted JSON body:

{
  "Title": "New Item",
  "Description": "This is a test"
}

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Step 3: Test & Debug the Flow

✅ Run the flow with sample data to check if all values are correctly passed.
✅ Use “Compose” actions to preview values before sending them to other actions.
✅ If a parameter is missing only sometimes, use error handling (Configure Run After) to handle failures.

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Step 4: Prevent Future Missing Parameter Errors

• Use default values or coalesce() in expressions.
• Add validation steps to check for missing inputs.
• Enable error handling in key actions.
• Test the flow with different scenarios before deployment.