[Reader][Win7] 21208 update breaks Acrobat Reader, won't start, missing dll

I found a 32-bit Api-ms-win-core-winrt-l1-1-0.dll  on dllme.com  also.  it identifies as  version 10.0.9904.0   It has a file date of 9/18/2025.  It is  13,192 bytes.  I dropped it into C:\program (x86)\Adobe\Acrobat Reader DC\Reader only and everything seems to be working OK.  I think I finally killed the nuisance AdobeCollacSync  service and process  also (fingers crossed). 

I deleted the .exe. and added a registry DWORD  bNeedSynchronizer = 0  here,  HKEY_CURRENT_USER\Software\Adobe\Acrobat Reader\DC\Workflows     appears good, no err messages.

With windows seven - 7

I cured my problem on two machines, by downloading the

32 bit  - Api-ms-win-core-winrt-l1-1-0.dll - (date modified-11/08/2016)

and placing a copy of the .dll file, in the following Folders.

Reader  (C:\program (x86)\Adobe\Acrobat Reader DC)

NGL   (C:\program (x86)\Adobe\Acrobat Reader DC\Reader)

Plug_ins  (C:\program (x86)\Adobe\Acrobat Reader DC\Reader)

System32  (C:\Windows)

Now works like a dream, back to normal.

Also I wont allow any auto updates on windows.

Windows 7 PC, 64 bit cpu, in UK

Acrobat Reader automatically updated on 19/02/26 to version 25.001.21223

and now won’t start due to missing file api-ms-win-core-winrt-l1-1-0.dll

It seems that all we need to do is download the missing file(s) and copy them to the required folders:

64 bit version for folder System32

32 bit version for folder SysWOW64

We may not need both but I found that just downloading the 64 bit version did not fix it, so I also downloaded the 32 bit version. These files are different, so don’t copy one as the other.

Once done Acrobat started ok. I did not even need to re-boot my pc.

By installing these missing files, even if Acrobat updates again to another version we should still be ok. It may not be possible to stop Acrobat updating itself.

Follow these simple steps:

1. Go to this website

https://www.dllme.com/dll/files/api-ms-win-core-winrt-l1-1-0

2. Scroll down and click on the large DOWNLOAD (in pink)

(Ignore any of the Ads that appear – don’t click on them)

(Ignore anything that says ‘Click to Continue’ – these are ads)

3. Get 64 Bit version

Many different versions of the file are shown (most have same version number)

Scroll down and locate the x64 - 64 Bit one (the first one for version 10.0.9904.0 will do)

Click on DETAILS (in pink), and then START DOWNLOAD (in pink)

4. This file will be in your explorer downloads folder

api-ms-win-core-winrt-l1-1-0_x86-64

It’s a zipped file so double click on it and explorer will unzip it

Copy the file shown api-ms-win-core-winrt-l1-1-0.dll

to C:\Windows\System32

You will see other api- files there

5. Get 32 bit version

Many different versions of the file are shown (most have same version number)

Scroll down and locate the x86 - 32 Bit one (the first one for version 10.0.9904.0 will do)

Click on DETAILS (in pink), and then START DOWNLOAD (in pink)

5. This file will be in your explorer downloads folder

api-ms-win-core-winrt-l1-1-0_x86

It’s a zipped file so double click on it and explorer will unzip it

Copy the file shown api-ms-win-core-winrt-l1-1-0.dll

to C:\Windows\SysWOW64

6. Once both files have been copied, just start Acrobat Reader.

OTHER INFORMATION

If you previously uninstalled Acrobat and it now won’t re-install, get the latest version from here:

https://get.adobe.com/reader/enterprise

Select Windows 7 and English (UK)

There is only one version

Reader 2025.001.21223 English UK for Windows (32 bit)

It fixed the issue for me:

Download and install this specific version: 

https://ardownload3.adobe.com/pub/adobe/reader/win/AcrobatDC/2500121111/AcroRdrDC2500121111_en_US.exe

IMPORTANT: After installing, DO NOT open Adobe Acrobat Reader yet. You must follow these 4 steps first to block updates:

STEP 1: SERVICES

* Press [Win + R], type "services.msc", and press Enter.
* Find: "Adobe Acrobat Update Service".
* Action: Right-click -> Properties -> Startup type: Disabled -> Stop -> OK.

STEP 2: TASK SCHEDULER

* Open Start Menu, type "Task Scheduler", and open it.
* Action: Click "Task Scheduler Library" (left side).
* Action: Right-click on “Adobe Acrobat Update Task” and select "Disable".

STEP 3: STARTUP APPS

* Press [Win + R], type "msconfig", and press Enter.
* Action: Go to "Startup" tab and UNCHECK:
[ ] Adobe Updater Startup Utility
[ ] Adobe CS6 Service Manager
* Action: Click Apply and OK.

STEP 4: HOSTS FILE

1. Open Start Menu -> All Programs -> Accessories.
2. Right-click "Notepad" -> Run as Administrator.
3. Go to File > Open. Path: C:\Windows\System32\drivers\etc
4. Change bottom-right filter to "All Files (*.*)".
5. Open "hosts" and paste these lines at the end:

127.0.0.1 activate.adobe.com

127.0.0.1 practivate.adobe.com

127.0.0.1 ereg.adobe.com

127.0.0.1 update.adobe.com

127.0.0.1 swupdl.adobe.com

127.0.0.1 genuine.adobe.com

6. Save and Close.
 

Now you can use Adobe and open your PDF files normally with this older version, without worrying about it updating to the latest version that is incompatible with Windows 7.

anche io ho avuto lo stesso problema su w7 con acrobat reader aggiornato . Ho risolto  installando su un pc con w10 il pacchetto Visual Studio 2026 completo. Ho poi cercatio a fine installazione la dll mancante e copiata sul pc con w7 nel direttorio di acrobat.

Ha funzionato subito

Another user with ancient W7 system here suffering from the same problem - and urgently need to do notes for important neuro-surgery appointment on in 2 days time and can’t access any of the reports I need to reference to do my notes/questions from.
Tried doing a re-install as per the pop-up - nope - still sulking and told me to “go away”.
However - when when I did a right-mouse-click on the file in File Manager to see what options might be available I found I was able to open the pdf files some free file viewer program I must have downloaded at some point, so maybe this will help others.
The program that opened the pdf files was “File Viewer Lite”.
https://windowsfileviewer.com/download 
It pisses me of that I can’t even open Adobe to try and turn off any automatic updates - which I thought I had already turned off because of using a computer still running W7 :( :( :(

Adobe is the worst. Happened here too. Should fire their programmers. Will go to Nuance for our pdf needs, have convinced two others to do the same. Ba-bye Adobe !

Here is latest update on my trying to restore a usable Adobe Reader version on Windows 7.  On 21 Feb morning I did all the things shown in this thread:  (1) removed broken version 25.001.21xxx  (2) cleaned traces with AdobeCleaner (3) loaded 32-bit version 22.003.20282  (4)  disabled Reader updater in Computer Management and in Services (5) changed the Adobe updater registry key from “3” to “0” - this is supposed to absolutely disable downloading and installing Adobe updates, (6) tested.   Did this on 4 computers.  All worked fine…..until approximately noon.  Then they all broke …..  version 25.001.21223 downloaded and installed anyway.  Adobe does not even recognize and conform to its own settings, especially the registry setting that says “no updates”.  It appears that Adobe is bypassing the update settings by simply forcing a totally new version on the user.

THIS IS INTOLERABLE.  Adobe has no business forcing updates/versions on users who do not want them, especially when the updates will no longer work.  The USER should be given the option whether or not to update, after the USER is told the consequences.  Adobe has no excuse to say “we no longer support Windows 7”… the users are NOT asking Adobe to “support” older Windows 7 versions….they are only asking that the working older versions be left alone.  If the user is happy with (or must use) these older versions ..  albeit with no further support .. they should be allowed to do so.  Microsoft no longer supports Windows 7 or 10, but even Microsoft does not force downloads on these users that disable the OS. 

Suppose I took my 2012 Toyota in for service at a dealership, and the dealer disabled the vehicle because it does not have all the electronic convenience/safety stuff that the later models have.  Does the dealer have that right, or do I still have the option to continue using the vehicle.

In this situation, Adobe could make the missing .dll available via download if that is all it would take to make the older versions function.  It is too risky to download this .dll for an unvetted source. 

Many older users (and my wife and I are in this category) do not have the means to continually buy new computers, and most do not have the computer knowledge to adapt older computers.  My wife said she had no ideal what to do when this error message appeared...she was in tears.

Adobe’s attitude is “WE know better than the USERS”.  If I look up the definition ARROGANT in Webster’s dictionary, I see the Adobe logo in the definition.  

For now, I must try to use Sumatra-pdf - it appears to meet my needs.

I created a little batch script and instructions to fix it, as I get dozens of error reports now so that I wanted to automate the crucial steps of the process, maybe it helps some of you.

If you have to use Acrobat Reader, here’s a list of download links to older versions (offline installer, DE and US version).

For private use, there are free tools that, in my experience, are faster and more flexible, for example SumatraPDF or PDF-XCange Editor (free version). At least they can help until Adobe has fixed the problem.