Excel file downloaded from Dropbox does not open

[BasicUserDE]

I have recently started experiencing the following (on a Windows 10 Enterprise, Version 20H2 and OS build 19042.1526 machine). When I download an Excel file from Dropbox and want to open it locally (MS Office365 Excel app in Windows 10), I first started receiving the error message that the file cannot open in protected view.

After clearing the three checkmarks in the Excel Trust Center settings for "Enable Protected View for files originating from the Internet, Enable Protected View for files located in potentially unsafe locations" and "Enable Protected View for Outlook attachments", this message disappeared. However, Excel seems to be attempting to open the file (as it generates an owner file that I can see in the file explorer), but then closes without opening the file (likely crashes, as when I enter Excel I can see the file being suggested for recovery, which also does not work). Marking to "unblock" the file in its properties also did not help.

Is this issue related to Dropbox or Excel?

This did not happen previously, and the file is still accessible in the Dropbox-embedded Excel, and other Excel files (not originating from Dropbox) also work fine (hence, Excel seems to be operating fine).

[Walter]

Hey @BasicUserDE, sorry to hear you're having issues with this. 

Could you please send us a screenshot of the exact error you're getting in order to have a visual as well?

Also, how exactly are you downloading the files? Are you using the website or the desktop app by any chance?

Any additional information is more than welcome!

[BasicUserDE]

Hi Walter,

Thank you for your support!

With the initial settings in the Excel Trust Center settings to enable protected views (see first screenshot below), I get the error message shown in the second screenshot below. I don't know if this is due to a recent update on the Microsoft side, as none of this was happening before (with the exact same settings).

Once I remove the three checks in the Excel Trust Center, the error message does not appear anymore, and - as mentioned - Excel seems to attempt to open the file (as an owner file (hidden, with $ in its name)) is being created. However, then Excel does not open.

With any other Excel file, I am not experiencing these issues, Excel seems to be working just fine.

I am downloading the file from my Dropbox using the Dropbox website an the "download" button therein. Again, this very same procedure used to work just fine until recently.

[Walter]

Thanks for the additional details and the screenshot too @BasicUserDE

Could you clarify if this happens with only one specific file or others as well?

Also, do you get any different results if you download the file through another browser?

While we're at it, are you able to preview this file normally on our website? 

[BasicUserDE]

@Walter I have no other reference file to compare this behavior against, as this is the only Excel file I have in my Dropbox.

I have tested the exact same process steps I laid out before using Microsoft Edge, with the same results (file being downloaded, but Excel crashing when trying to open). I normally use Google Chrome.

With both Edge and Chrome, I cannot preview the file in Dropbox. Opening it with the embedded Excel app in Dropbox, however, works just fine.

[Walter]

Thanks for the additional information @BasicUserDE

Could you please clarify the file type you're noticing this on and if you're running the latest version of MS Excel on your computer? 

Also, did you reboot your device since you first noticed this?

Let me know when you get the chance and we'll take it from there. 

[BasicUserDE]

@Walter as I am using a commercial Microsoft 365 subscription, I suspect that my Excel is a fairly recent (if not the newest) release. It is MSO (Version 2201 Build 16.0.14827.20198) 64-bit.

The file type I am noticing this on is xlsx (so no macros, VBA code or similar included in the file).

I have rebooted my computer several times since I first witnessed this behavior, with no changes to the result.

[Walter]

Do you happen to have any 3rd party apps or programs that might be monitoring your files @BasicUserDE?

An antivirus or a 3rd party app for backup purposes for example? 

If so, could you temporarily disable them and try to see if you get the error again?

[BasicUserDE]

@Walter I do, as I am on a business laptop. Due to the same reason, however, I cannot disable them (my employer's IT organization certainly could).

Before going that route, I tried the previously described procedure with my personal laptop, which is not nearly as well protected (only has an antivirus program on it) - again using the latest version of Google Chrome and a slightly more dated Excel version (Office Professional 2013) than on my business laptop.

In this case, while trying to open the file, Excel tells me that the file is damaged and cannot be opened.

If the file indeed were corrupted, this would put me in a very difficult position, as this file I am trying to retrieve from Dropbox is important, and I was planning to continue to work with it locally on my computer(s). What however speaks against this - in my opinion as a non-technical person - is that the web Excel version embedded into Dropbox continues to successfully open the file and allow me to interact with it.

[Walter]

Thanks for the additional information @BasicUserDE

May I reach out via email to have a further look internally?