Microsoft Outlook is the preferred email client. It's very productive, and anyone can use it for personal or official purposes. Its ease of integration with Microsoft products and Exchange connectivity is its most notable advantages over other competitors. Despite being so popular, there are still some issues. The most common error is "The set cannot be opened"

Although this error has been reported by many users around the world, its cause remains a mystery. Experts believe the problem is due to an incorrect Outlook configuration. These errors can also be caused by a corrupt PST file that is linked to your account.

We have great solutions that can be used to correct the error "outlook the set of folders cannot be opened" even if there are no obvious causes. Let's look at each of these options more closely to fix the problem.

Solutions to Fix the "Set of Folders Cannot be Opened" Error

Before you decide to go ahead with any solution, make sure that your system is running as an administrator. Outlook should not be running in the background or on the system.

The best solutions to the problem "cannot open Microsoft Outlook" are the following:

  • Work in a Safe Mode
  • Outlook Launcher from the Taskbar
  • Reinstall MS Office
  • You can disable your account in the Mail app
  • Repairing OSTs or PSTs
  • Use an app password

Solution 1 - Working in Safe Mode

You should not be unfamiliar with the safe mode as it is one of the most popular options for making an application work. To fix the error "The set of folders cannot be opened", you can use safe mode in Microsoft Outlook. Follow these steps:

  • Open Run command, type in "Outlook/safe" and hit the Enter key.
  • Next, select your Outlook profile, and then click "Add to My Outlook Credentials" if you are asked.
  • Safe Mode will allow MS Outlook to start working. If your MS Outlook is still working well, you can disable add-ins to fix the error "The set cannot be found".
  • Select Options from the File menu.
  • Click on the Add-ins tab, select Com Addins from the dropdown menu under the Manage section, then press OK.
  • To close the window, uncheck all add-ins. Click the OK button.
  • You are now ready to go.

Solution 2 - Launch Outlook from the Taskbar

The cause of the error, as mentioned earlier, is unknown. The error "The set of folders could not be opened Outlook 2016" can be avoided by opening Outlook from your taskbar. It isn't a permanent solution to the error "the list of folders can't be opened Outlook 2016", but it is an alternative that you could consider if you don’t want to spend too much time pondering long solutions.

Solution 3: Reinstall MS Office

Microsoft Outlook is part of the MS Office package. There is a good chance that you can fix the Outlook 2016 folders not opening error by reinstalling MS Office. This would cause Microsoft Outlook to reset.

A 64-bit package is better than a 32-bit. Only a few cases have been reported of these errors in the 64-bit version. It is therefore a great choice to resolve the error "The set of folders can't be opened".

Solution 4: Repair OSTs & PSTs

Corrupt Outlook data files may easily lead to the "Microsoft Outlook the set of folders can't be opened" error. These steps will help you fix such a file.

  • Run exe from MS Office files found usually in Local Disk, (C).
  • To start scanning, select the file you wish to repair and click the Start button.
  • Click on the Repair button after scanning to repair the file.

Solution 5 - Disable your account from the Mail App

  • Open the Mail app and go to Account Settings.
  • Select your Email Account after clicking Manage Account.
  • Next, click the Delete Account button.
  • Close the confirmation message, restart your system and remove "The set of folders could not be opened".

Solution 6 - Delete XML Files From Directory

  • Tap the Enter key to enter the App data into the Run app
  • Go to C:\Users\Fujitsu\AppData\Local\Microsoft\Outlook and delete or move the XML files.

These are just a few of the many solutions that can be used to fix errors such as cannot open Microsoft Outlook, a set of folders not opening, a set of folders not opening, etc. These methods won't give you the guarantee of the latter. I wouldn't recommend that you spend your time or effort on these methods.

An alternative solution such as DRS Outlook Outlook PST Repair Software is a better choice. It has many valuable technical features such as log file creation and recovery of corrupt PST files. This tool can solve all your Outlook queries.


The "the set of files cannot be opened" error was addressed and we learned several methods to fix it. These include repairing PSTs and reinstalling MS Office. You also learned which third-party software is best for this. I trust this blog has helped you to resolve your technical questions.