Error message: Decryption failed(null) when attempting to open an Excel document on iPad

Interim Success

Ok, I've found an interim solution though I still believe Apple has an issue since I have read that 14.1 does not have this problem but at least this works for now.. .. and don't believe that the issue lies with Dropbox, Synology DS File, Microsoft, etc, the issue is with Apple and they need to fix what they broke.

I took the Excel password protected file that I could not open directly from with the Apple Mail app on my iPhone 12 running iOS 14.2 (the same exact file worked fine in 13.6) and instead of opening it, I long pressed it in Mail until I got a pop up menu with choices. I like choices :-) I chose to Save that file in the Apple "Files" app on my phone. The File app comes standard with iOS. I then opened the Files app and tapped the password protected Excel file I just put there, it prompted for a password, I entered it and it opened just fine. 

However, in order to get success, you first have to go to the Apple App store and download the free "Microsoft Office app for iOS", (see pic). Once downloaded to your phone you do not need to sign in to it or even have it open, just the fact that its on the same device as the file you want to open does the trick. The Excel file opened it in Excel.

I will assume this same procedure will work for Word and Powerpoint but haven't tried it yet.

So until Apple fixes the issue, there is another way to open a password protected Microsoft Office file on an iOS device running iOS 14.2

Ok folks, Apple has now fixed the issue, download and install iOS 14.4 and start using your password protected files as you used to. I did and verified it works.

Note: You will not find any mention of the issue under the Fixed Bugs section of the update

bookbean329, don't hold your breath for a solution from Apple on this issue as it may not actually be a bug, rather an intentional change. Therefore I encourage you to find your own long term solution that you like. I've been able to open password protected files in a few different ways on my iPhone 12 running 14.3

• First: I use iTunes to transfer the file from my computer into my iPhone and then sync ( I have a Mac)
• Second: I simply go to Finder (on a Mac, which is the same as File Explorer on a PC), find the file I want to put on my iPhone, right click it and choose AirDrop (for all you Mac users out there), not sure if a Windows PC support this or has an equivalent. I then AirDrop it which basically just transmits the file over my local network and I accept it on my iPhone and it goes to the Apple Files folder automatically. I like these two methods because my file never has to leave my local network
• Third: I can email the file to myself and then once received, I long press it and get options of which I select Save and it saves it to the Apple Files folder. I don't particularly like to send password protected files via email but this works when I am not at home

Ok, once its on my phone, when I open it, the phone automatically sees the extension as one from Microsoft and since I have the free MS Office app that I downloaded from the Apple App Store on my phone, it opens MS Office and then presents me with the password entry field and subsequently opens the file in its native Microsoft app. It does all this within a second or two or as fast as my fingers can travel.

Hi feliciafromnashville,

Thanks for the clarification. I have pasted below what I posted earlier in this thread, see if this works for you. First, sign out of MS Office, I never signed in and it works all day long for me. I'm not saying it won't work if you sign in but if you can do a carbon copy of what worked for me and get it to work for you, then you can experiment from there to find the best way for you. By the way, once I opened the file, the MS Office app copied it and now whether I open it from the Apples Files app or the MS Office app, it opens after putting in my password.

Here is what I wrote. ..

I took the Excel password protected file that I could not open directly from with the Apple Mail app on my iPhone 12 running iOS 14.2 (the same exact file worked fine in 13.6) and instead of opening it, I long pressed it in Mail until I got a pop up menu with choices. I like choices :-) I chose to Save that file in the Apple "Files" app on my phone. The File app comes standard with iOS. I then opened the Files app and tapped the password protected Excel file I just put there, it prompted for a password, I entered it and it opened just fine. 

However, in order to get success, you first have to go to the Apple App store and download the free "Microsoft Office app for iOS", (see pic). Once downloaded to your phone you do not need to sign in to it or even have it open, just the fact that its on the same device as the file you want to open does the trick. The Excel file opened it in Excel.

This is a reply to clear up most of the complaints on this issue. I went to IOS14.2 on my iPhone8 and my iPad and encrypted files that used to work didn't any more. I use them infrequently, and didn't notice until Apple (pretty quickly, it seems, after 14.2) released 14.3. Applied it to both the phone and the pad and happened to need to open one of the encrypted Word files (made with Word 2007 because I can't see the benefit of Office 365). I got the Decryption failed(null) message on the word file.

I'm still at 14.3 and from reading this thread I heard about the Word app.

Downloaded it and now both files reside in a folder named Word (because it's there and a handy place to put them) and they decrypt just fine.

App Store version for Word and I expect for Excel is an excellent workaround.

But the IOS Developers and Testers need to develop some use cases that are off the beaten path for us Mainframe and PC geezers.

I have a problem with the way Microsoft pushes updates out with no choice below the Enterprise versions I would really hate to see Apple take the same course. I know Steve's dead now, but I believe that if he wanted to, he would come back down and take control. He's the Root Commander of the universe.

Anyway, the Word App was free but I had to sign in to the App Store with my AppleID and password and then, for some reason, to Microsoft with my MSID and password.

I contacted Apple care support and after three escalations finally got to level two and was told they are aware of the issue and are working hard to resolve it but in the meantime open the documents with Excel.

Like Bgnmarty I do not have a Microsoft Office subscription but you can install the MS Office app for free via the Apple App Store. Once it’s on your iPhone/iPad you can use it to open and view an encrypted MS Word or Excel file. You don’t need a subscription. I haven’t tried Bgnmarty’s method of saving it to “Files” as I keep my MS documents on Dropbox and the workaround works ok from there. This is how it works for me:

1) open Dropbox on my phone

2) tap the encrypted file I want

Dropbox tells me the file is password protected and opens a dialogue box asking for the password

At the same time, at the bottom of the Dropbox window is a blue button labelled “OPEN”

3) Ignore the dialogue box and tap the “OPEN” button. It asks if I want to open the file in Excel or cancel

4) Tap Excel and Excel loads and the file opens (after a while) and also has the dialogue box asking for the password

5) Enter password and the file opens.

Now, here’s the weird bit; most of the time if I try to edit the document in any way it asks me to log in to my Office365 account, (which I don’t have!) but sometimes it just lets me edit, copy, paste, enter new rows, etc.

I usually only want to read the document so not being able to edit (usually) doesn’t matter. (I can do that on my Mac with Office 2011 installed.) It’s still annoying though that iOS 14.2 has *******d up what worked perfectly well previously.

There IS still a problem Kipper300 and the answers are on this thread as Bgnmarty says but I too have found the thread a little awkward to follow. So, for the sake of simplicity the answer is to download the free Microsoft Office app (or you can just download the Word app if you prefer) and use that to open the password protected file. This is how it works for me. I keep an encrypted, password protected spreadsheet on Dropbox. If I try to open it directly from Dropbox I get the "null" response. But I also get the option to OPEN in Excel as I've got the (free) app on my phone and iPad. Click on it and Dropbox opens Excel. I get a "Server cannot be found" message - presumably because I've not got an Office 365 subscription but I just ignore that as behind it is the dialogue box to input the file password. I can only read the file, no editing, but that's all I need. Bgnmarty's answer may be simpler so give that a try too, see what works best for you. It does seem that the problem lies with the iOS 14.2 update so hopefully Apple will provide a fix at some point.

I do not like Microsoft (I do like Excel though) and would never do anything that would actually cause me to have to pay them a freak'n dime if I can avoid it :-) I downloaded the free MS Office app from the Apple app store, I did not even sign into the MS Office app, apparently just having it on my phone was enough as the iPhone knew what to do. When it sees the file extension of what you want to open, it searches all your apps on your device to find one that will open it.

Not sure what you mean in your second sentence about accessing the folder and swiping as I don't do any of that. Here is my procedure.

1. Open the Apple Files app and I can see all the files I have in there with various file extensions
2. I touch the password protected Excel file I want to open
3. I can watch the phone automatically open MS Office and it immediately presents me with the field to type in my password
4. I type in the password and the file opens in Excel

Pretty simple and very fast. Here are some screenshots from my iPhone running iOS 14.2.1

I figured out a temporary work-around until Apple fixes this. I converted my password protected Word document to a PDF, password protected the PDF, and then sent it to my iPhone. The decryption error does not occur with a PDF file.

Thank you for this. My issue wasn't exactly the same though, it was that I couldn't open the protected files in the iOS Dropbox app. Anyway, the difference to your advice was that instead of opening the file, I chose to Export to the MS Office app (which I downloaded following your advice).

Worked perfectly.

Also, I've just updated iOS to 14.3 and no such luck fixing the issue via Dropbox.

Finally! 14.4 works, can now view encrypted files directly from Dropbox. May not be entirely Apple’s fault. I read on a Dropbox thread that their engineers were working on it too. Could be a joint effort.

hello i dowloaded Office for IOS from the Apple store and use it to open the files. It works

Go to the App Store and download the free Excel app.

After some trials i found out i could send a copy within the Synology App to Excel or Office and then the file opens after entering the password. So at least i could confirm it works as a workaround.