Summary
After editing an Excel `.xlsx` file using Telerik RadSpreadsheet and saving it via the default Save option, the saved file becomes corrupted. It no longer opens in RadSpreadsheet (throws an error) and shows a repair warning in Microsoft Excel.
Reproduction Steps
1. Upload an Excel `.xlsx` file to the `ABC` folder on the server.
2. Load the file in RadSpreadsheet via a basic viewer page.
3. Make any small edit (e.g., change a cell’s value).
4. Click the built-in Save option in the RadSpreadsheet toolbar.
5. Attempt to:
- Reopen the saved file in RadSpreadsheet → Error: Object reference not set to an instance of an object.
- Open in Excel → Warning: “We found a problem with some content in ‘filename’. Do you want us to try to recover as much as we can?”
Files Attached
- `Original.xlsx` — Before editing, opens fine in both RadSpreadsheet and Excel.
- `Modified.xlsx` — After saving via RadSpreadsheet, causes errors.
- Screenshot of:
- RadSpreadsheet error :
- Excel repair prompt
Code Snippet :
<telerik:RadSpreadsheet ID="sample" runat="server" Visible="false" style="font-size: 10px;" />
protected void Page_Load(object sender, EventArgs e)
{
string fileName = (string)Session["SelectedFileName"];
SheetLoad(fileName);
}
private void SheetLoad(string fileName)
{
try
{
string filePath = Server.MapPath("~/ABC/" + fileName);
if (!File.Exists(filePath))
{
string errorMsg = "File not found: " + filePath;
ClientScript.RegisterStartupScript(this.GetType(), "alert", "alert('File not found!');", true);
return;
}
// Load spreadsheet using Telerik document provider
sample.Provider = new SpreadsheetDocumentProvider(filePath);
sample.Visible = true;
}
catch (Exception ex)
{
string errorMsg = "Error opening file: " + ex.Message + " | File: " + fileName;
ClientScript.RegisterStartupScript(this.GetType(), "alert", "alert('Error loading file!');", true);
}
}
**Observation:**
* This only happens for **some files**, especially ones that likely contain advanced Excel features.
* Other simpler files save and reload without any issue.
**Assumption:**
It seems the default save behavior of RadSpreadsheet is **not preserving some Excel structures**, leading to file corruption on save.
Dear Telerik Support. I found another bug related to this one below.
This line of code also causes the same issue.
$find("txtYear").clear();
See attached Console debug output.
It is my opinion that a hot fix needs to be done asap! The work around that Derek posted on May 23rd falls short of the bigger issue. This is a serious matter and needs to be addressed immediately.
Yes, ASP.NET Webforms is outdated, but it's still around, and I think many developers are looking at moving to a newer and more modern technology. But in some cases - including mine - it's not really possible to refactor an application that has grown for 20 years overnight. The only thing I can do is put a lot of energy into changing the CSS of the controls. Which is not always easy.
I really appreciate the functionality of the Telerik controls and think it's a shame that they don't get a visual and functional update.
In this specific case, it is about the Datepicker Control, which has a different behavior than the more modern version under .NET Core. For example, the month or year selection opens in a new DIV popup. In the more modern control, this is solved in a more elegant and modern way.
I think that this list of controls that need a “front-end pimp” can certainly be extended.
Thank you!
Based on Ticket ID 1683806 it was suggested to add this here. It should be fairly straight forward and would resolve issues that I have.
My Suggestion:
Why can you not just add the clientEvents to the RadEditor1.FileExplorerSettings
Something like RadEditor1.FileExplorerSettings.ClientEvents.OnClientFileOpen="somefunction"
Your response.
Thank you for your suggestion to add client events directly to RadEditor1.FileExplorerSettings. It's a thoughtful idea that could indeed enhance client-side flexibility and streamline interactions.
At present, this feature is not available. However, we encourage you to submit it as a feature request through our public feedback portal, where our product team actively reviews community input for potential inclusion in future updates.
Also, please see my ticket for a bug in the ImageManager using th URL to return the item instead of the OriginalPath. This makes my custom content provider not feasible.
Thanks!
Hi,
Would it possible to build in a text search filter into a Listbox?
Re: https://www.telerik.com/account/support-center/view-ticket/1677442
Re: https://www.telerik.com/products/aspnet-ajax/documentation/knowledge-base/listbox-client-side-filter
Alan
Business Need - User Story Terminology:
As a Telerik Support Specialist, I would like our programmers to incorporate new code which will treat hyphens as if it were a space upon ExportToPdf() so that we gracefully handle for scenarios where a very long word with a hyphen will wrap to the next line instead of overlapping other content.
Hi,
I was looking around to develop a web app that allows streaming camera view in order to take pictures, showing the previews, letting cancel/retake or transfer (upload/save) them.
I started from the input control, that makes more or less what I need, but start a video streaming, letting the user simply to capture frame from it to save pictures, is more user friendly and simplify a lot the workflow.
So I started to work with video element, canvas and FloatingActionsButton, hitting against many issues, starting from the different browsers compatibilities.
I was just wondering if Telerik would never implement such a camera + gallery component, in order to take and manage pictures easily and cross platform.
Thank you, kind regards