Excel popup on opening "This document is both encrypted and password protected"

12300314 126 Reputation points
2021-07-20T15:33:09.303+00:00

Hi there,

I have a user who has the following popup every time they open Excel, even if they are not opening a document directly:

116316-image.png

The version of Office is Microsoft 365 MSO 16.0.14131.20296 64-bit.

I have found a number of older posts related to this issue (such as this one) that all recommend creating a reg key under HKEY_CURRENT_USER\Software\Microsoft\Office\12.0\Common\Security, however as I am on the latest Office, I only have 16.0. I have tried to create the "Security" key and then the DWORD value in my corresponding 16.0 folder but it makes no difference.

I have also tried both a quick and online repair of Office.

Any other suggestions would be greatly welcome.

Windows 10
Windows 10
A Microsoft operating system that runs on personal computers and tablets.
10,705 questions
Office Management
Office Management
Office: A suite of Microsoft productivity software that supports common business tasks, including word processing, email, presentations, and data management and analysis.Management: The act or process of organizing, handling, directing or controlling something.
2,012 questions
Excel Management
Excel Management
Excel: A family of Microsoft spreadsheet software with tools for analyzing, charting, and communicating data.Management: The act or process of organizing, handling, directing or controlling something.
1,649 questions
0 comments
Accepted answer
  1. 12300314 126 Reputation points
    2021-07-30T13:55:49.223+00:00

    Hi all,

    I have solved it - a fairly obvious solution I did not consider for some reason. I created the NoPromptForRC4Encryption key (and set value to 1) under HKEY_CURRENT_USER\SOFTWARE\Microsoft\Office\16.0\Common\Security and I am no longer receiving the prompt.

    Thanks for all your help.

    Thanks,
    Jamie

    2 people found this answer helpful.
    0 comments

3 additional answers

Sort by: Most helpful
Most helpful Newest Oldest
  1. Emi Zhang-MSFT 22,086 Reputation points Microsoft Vendor
    2021-07-21T06:11:03.237+00:00

    Hi @JamieHassallClarke-8015,
    Based on your description, this problem only appear in a specific user.
    Did this problem appear in all Excel Workbooks or specific Workbook? Where did you store the file?
    Try this method:

    *HKCU\Software\Microsoft\Office\16.0\<application>\Security\Crypto*

    Create a registry key: CompatMode and set to 0.

    Try it and check the result, please let us know if you would like further assistance.

    If the response is helpful, please click "Accept Answer" and upvote it.
    Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.

  2. Stacy Clark 21 Reputation points
    2021-07-21T06:22:21.74+00:00

    Just do a Save As and save as the new format.

  3. Lz._ 8,991 Reputation points
    2021-07-21T14:25:33.117+00:00

    Hi @JamieHassallClarke-8015

    Fixing this kind of issues isn't in my area of expertise + I really don't like
    When my PC becomes unstable (very very rare) for a reason or another most of the time I clean-up the room and re-install as my experience tells me that trying to fix something I don't really understand or that should not happen: 1) Can take a lot of time; 2) Risk is quite high that the fix will only be a short-term one and I'll face some other issues later

    If it was me, given there's only have 1 user experiencing the issue I would be very pragmatic:

    • See if issue persists starting Excel in Safe Mode
      If no issue, it's highly probable there's an add-in or something similar that's the root cause
      Check the content of XLSTART folder, just in case
    • If issue persists in Safe mode, create a new user account on that PC
    • If issue persists with a new account => Office uninstall support tool > Re-install

    Hope this makes sense