Fix: iCloud Outlook Sync MAPI APLZOD.DLL Error

The Outlook sync feature with the iCloud has proved to be a great add-on for users. They can easily sync all their email, calendar and contacts to their iCloud account. Once you have data in your iCloud, you can easily sync it across all your Apple devices.

However, recently many users started complaining that the two applications didn’t sync. The started to get an error message which stated “The set of folders cannot be opened. An unexpected error has occured. MAPI was unable to load the information service C:\PROGRAM~2\COMMON~1\Apple\INTERN~1\APLZOD.DLL”

The usual fixes for these type of problems are signing out or re-installing iCloud but this didn’t work for any of the users. After some digging, it was determined that this error was due to a security update for Microsoft Office Outlook 2007 (KB3191898). We have listed a couple of solutions to fix this problem. Start from the top and work your way down.

Solution 1: Change ‘AllowUnregisteredMapiServices’ Registry Value to 1

We can try changing some registry values on your computer to fix this problem. Do note that Windows Registry Editor is a powerful tool and changing keys you don’t know about can hamper your machine. Follow the instructions carefully.

  1. Press Windows + R to launch the Run application. Type “regedit” in the dialogue box and press Enter. This will launch the Registry Editor of your computer.

  1. Once in the registry editor, navigate to the following path using the navigation pane present at the left side of the screen:


  1. Here you will find a DWORD named as “AllowUnregisteredMapiServices”. Double-click it to change its value.

  1. Change its value from 0 to 1. Press Ok to save changes and exit.
  2. A restart might be required for the changes to take place.
  3. After the restart, refresh your Outlook and iCloud and try syncing them again.

If you don’t find the specific registry value, you can add it and set its value accordingly. Follow the steps below.

  1. Right-click on an empty space at right side of the window and select New > DWORD (32-bit) Value.

  1. Name the new key as “AllowUnregisteredMapiServices”. Double click it to change its value and set it to “1”.

  1. Press Ok to save changes and exit. Restart your computer and after refreshing Outlook and iCloud, try syncing them again.

For users who don’t use group policies, they should navigate to this address rather than the one specified in step 2.


Solution 2: Creating the correct file using cmd

The reason why we are having this problem is because the DLL file after the update isn’t the same as it was before. We can fix this by copying the DLL file correctly.

  1. Press Windows + S to launch the search bar of your start menu. Type “command prompt” in the dialogue box. Right-click on the first result which comes forth and select “Run as administrator”.

  1. Once in the command prompt, run the following command:


This will change the current directory of the command prompt to where we are trying to implement the changes.

  1. Now run this command to create a copy of the DLL file with the correct name

copy APLZOD32.dll APLZOD.dll


  1. Restart your computer for the changes to take effect properly and check if the problem gets fixed.

Solution 3: Uninstalling the updates

If all the above solutions don’t work for you, we can try rolling back the update which started to cause problems for you. These steps are targeted towards Outlook 2010.

  1. Press Windows + S to launch the search bar of your start menu. Type “updates” in the dialogue box and select the first result which comes forth.

  1. Select the option of “Update history” present under the button of Check for Updates.

  1. Now a new window will come forth. Proceed with the option of “Uninstall updates”.

  1. Now right click on the Security update for Office Outlook and select Uninstall. This will uninstall the security update from your computer.
  2. Now head back to the updates window and select “Advanced options” present under the heading of Update settings.

  1. Scroll down until you find the heading of Pause Updates. Enable this setting and restart your computer for the changes to take effect.

  1. Check if the error message goes away and the applications started syncing again.

Kevin Arrows

Kevin Arrows is a highly experienced and knowledgeable technology specialist with over a decade of industry experience. He holds a Microsoft Certified Technology Specialist (MCTS) certification and has a deep passion for staying up-to-date on the latest tech developments. Kevin has written extensively on a wide range of tech-related topics, showcasing his expertise and knowledge in areas such as software development, cybersecurity, and cloud computing. His contributions to the tech field have been widely recognized and respected by his peers, and he is highly regarded for his ability to explain complex technical concepts in a clear and concise manner.