Power Platform Community Forum Thread Details

To resolve the issue where the error says the file extension is not valid, you can use a Compose step in Power Automate to ensure that the file name includes the correct extension before attaching it to the email. Here's how you can troubleshoot and fix this issue:

Step-by-Step Solution

1. Verify and Retrieve the File Extension

Add a Compose action to extract the file extension dynamically:
- Input:
  
  last(split(triggerOutputs()?['body/Name'], '.'))
- This retrieves the file extension from the original file name provided by the Microsoft Form or SharePoint.

2. Build the Full File Name with Extension

Use another Compose action to construct the file name with the correct extension:
- Input:
  
  concat(triggerOutputs()?['body/Name'], '.', outputs('Compose'))
- Replace triggerOutputs()?['body/Name'] with the dynamic content for the file name.

3. Apply the File Name in the Email Action

In the "Send an Email" action:
- For Attachments Name, use the output of the Compose step (built file name with the extension).
- For Attachments Content, use the binary output from the "Get file content" action.

Example Flow Configuration

Trigger: Microsoft Form submission.
Save Files to SharePoint: Use "Apply to each" to save each uploaded file to SharePoint.
Retrieve File Content: Use "Get file content" to fetch the binary data of the file.
Add a Compose to Extract File Extension:
- Use the expression to extract the file extension.
Add a Compose to Build the File Name with Extension:
- Use the expression to ensure the file name is constructed correctly.
Send Email with Attachments:
- Attach the file using the validated file name and binary content.

4. Debugging the Issue

To identify the problem, add a Compose action before sending the email to inspect the constructed file name and extension:

Add a Compose action with:

concat(triggerOutputs()?['body/Name'], '.', outputs('Compose'))
Run the flow and check the output in the run history.

Common Pitfalls and Fixes

No File Extension in Original File Name:
- Ensure the file uploaded has an extension. If not, you may need to add a default extension based on the file type (e.g., .pdf, .xlsx).
  
  if(equals(outputs('Compose'), ''), 'defaultExtension', outputs('Compose'))
Invalid Characters in File Name:
- Replace invalid characters in file names:
  
  replace(triggerOutputs()?['body/Name'], ' ', '_')

Final Steps

Test the flow with various file uploads to confirm the extension is always valid.
If the issue persists, inspect the output of each step in the run history, particularly the Compose steps, to ensure the file name is constructed correctly.

Let me know if you need further assistance! 😊