We are using Asp.Net version 3.0.0.0 of teh CuteWebUI.AjaxUploader on several pages on our site.

One page is loaded in an iFrame and displayed in a div styled like a modal dialog.

The page that is loaded in the iFrame has a asp:DropDownList, and a few asp validators. The page works fine in all browsers except FireFox 25.0.1.

When the iFrame/div is shown the uploader and page work perfectly, but when the div that contains the iFrame is hidden a JavaScript error pops up: "Error when initialize uploader : Ox19b.getComputedStyle(...) is null"

FireFox represents a small portion of our users, so we are going to use this version, but would like to know what we can do to prevent the error.

Below is the server tag for the page that causes the problem. 

<CuteWebUI:Uploader      

      runat="server"     

      ID="uplDocuments"     

      InsertButtonID="imgUpload"     

      MaxFilesLimit="1"     

      MaxFilesLimitMsg="Please choose only one file to upload at a time."     

      MultipleFilesUpload="false"     

      ShowProgressBar="true"

    ShowProgressInfo="false" > 

   <ValidateOption AllowedFileExtensions="pdf,gif,jpg,jpeg,png,doc,docx,txt" /> 

</CuteWebUI:Uploader>

I discovered that if I added a timeout to the JavaScript code that closes the div after the PostBack that uploads the file the error goes away.

I'm not sure what that means as far what is causing the error above .