Clear the Outlook Cache to Troubleshoot Web Add-ins

Overview

If Client-side Signatures is not appearing or behaving as expected in Outlook for Windows, clearing the cache can often resolve the issue.

This may help if:

• The add-in works in Outlook on the web but not in the Outlook desktop app.

• The add-in fails to load or apply signatures automatically.

Solution

Outlook Classic for Windows

1. Close Outlook completely.
   Ensure Outlook is not running in the background.

2. Open the cache folder:

   • Press Windows + R to open the Run dialog.

   • Type the following path and press Enter:

     %LOCALAPPDATA%\Microsoft\Office\16.0\Wef\
     

3. Delete the cache files:

   • Select all files in this folder and delete them.

   • This clears the cached data used by Outlook Web Add-ins.

4. Restart Outlook.

Note:
If the issue continues, verify that the add-in is correctly deployed and that you are using the latest version of Outlook.

New Outlook for Windows

1. Close Outlook completely.
   Ensure Outlook is not running in the background.

2. Run the following command:

   • Open the Command Prompt or Run dialog (Windows + R).

   • Enter:

     olk.exe --devtools
     

3. Open the DevTools window:

   • The New Outlook for Windows client and Microsoft Edge DevTools will open.

4. Clear the browser cache:

   • In the Microsoft Edge DevTools window, select the Network tab.

   • Right-click (or press and hold) anywhere in the Requests table.

   • Choose Clear browser cache.

5. Restart Outlook.