AsyncFileUpload not working first edit row

Hello,

If you are using the Async file uploader control in AJAX Toolkit inside an update panel. when you select a file to upload, after selection, the file uploader control will be showing with Red background in the text field.

The fix for this problem is: click on the properties of the async file uploader control -> find ClientIDMode property -> change it from inherit to Auto ID.

Now try to build your web app. and select a file, The control will show the selected file with green background which means it is a valid input file validation being done by the control itself.

There is some conflicts in your page. enableEventValidation will be true by default for the page. This will validate the aspx page to the server. Try making that false in your page directive.
Try this:

<%@ Page Title="" Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="Fire_PreQuote"
EnableEventValidation="false" %>

--Amit

Just add the ClientIDMode="AutoID" option to AJax control & everything will work like a charm

I had the same problem. I had a template field with an async file upload control in the edit and footer templates. Whenever I tried to upload the file in the first row, it gave this error. I went into the async file control in the edit template and changed the ClientIDMode to 'Static'. The problem went away. I left the ClientIDMode as 'AutoID' in the footer.