Excel Error Codes

Fix Excel 404 Error: Request Headers Too Long When Inserting Background

Natalie Taylor Oct 1, 2026 869 views

Question details

The user encounters a 404 request error stating that the request headers are too long when trying to insert a background into a worksheet.

How to Fix Excel 404 Error: Request Headers Are Too Long When Inserting a Background

Product: Microsoft Excel
Device & OS: not provided
Scenario: Attempting to insert a worksheet background image, even within a completely blank workbook.
Observed behavior: Excel fails to insert the background and instead displays a 404 request error indicating that the request headers are too long.

Before you start

Before troubleshooting, ensure you have a stable internet connection and try saving any open workbooks to prevent data loss during an application restart.

Solution 1Recommended

Disable Optional Connected Experiences

Turning off optional connected experiences in Excel's privacy settings often resolves the 404 headers error when inserting backgrounds.

Microsoft Office uses 'Connected Experiences' to fetch online images. A bug in this feature can cause the request headers to exceed the server limit, resulting in a 404 error even if you just want to browse local files. Disabling this feature forces Excel to bypass the broken online request.

Open Account Settings

Launch Microsoft Excel. Click on the 'File' tab in the top-left corner, and then select 'Account' from the bottom of the left-hand sidebar.

Access Privacy Settings

Under the 'Account Privacy' section on the right side, click on the 'Manage Settings' button.

Turn Off Connected Experiences

Scroll down in the privacy window until you find the 'Optional connected experiences' section. Uncheck the box that says 'Turn on optional connected experiences' and click 'OK'.

Restart Excel

Close Microsoft Excel completely. Reopen the application, open your workbook, and try to insert the worksheet background again.

Success Tip: This workaround should immediately restore your ability to insert local background images. You can turn the feature back on later if you need access to other online Office features.

Solution 2

Update or Repair Microsoft Office

If disabling connected experiences doesn't work, updating or repairing your Office installation can fix corrupted system files or bugs causing the network request error.

Free Microsoft Office alternative

Insert Spreadsheet Backgrounds Flawlessly with WPS Office

Tired of encountering the 404 request header error in Microsoft Excel? WPS Office is a free, lightweight alternative that allows you to seamlessly insert backgrounds and edit spreadsheets locally without cloud connection bugs.

1. Download WPS Office: Get the free WPS Office suite from the official website and install it on your device.
2. Open Your Workbook: Launch WPS Spreadsheet and open your existing .xlsx file or create a new document.
3. Insert Background: Navigate to the Page Layout tab and click 'Background' to smoothly insert your local image file.

100% compatible with Microsoft Excel (.xlsx, .xls) file formatsInsert worksheet backgrounds locally without 404 request errorsFree, lightweight, and incredibly fast to launchFamiliar user interface requires no learning curve

Frequently Asked Questions

Why does Excel say request headers are too long when inserting a background?

This error occurs because Excel's 'Connected Experiences' feature attempts to fetch online images via Microsoft services. If the generated browser or server request headers exceed the maximum byte limit, it triggers a 404 error, which interrupts both online and local image insertion.

Can I insert a background in Excel without turning off connected experiences?

Sometimes, clearing your Microsoft Office cache or resetting your default browser's network settings can temporarily bypass the issue. However, disabling optional connected experiences is the most reliable and immediate workaround.

Will turning off connected experiences disable other features in Excel?

Yes, disabling optional connected experiences will prevent you from using certain cloud-backed features. This includes inserting online pictures directly from Bing, using 3D Maps, and utilizing Smart Lookup.

Microsoft Office Error Codes