Fix “The set of folders Cannot be opened. An unexpected error has occurred”

If you are an Outlook user and get the error message”The Set of folders cannot be opened. An unexpected error has occurred” when you try to open your Outlook application and emails. Here, in this post, we are going to discuss how to fix “Cannot start Microsoft Outlook. cannot open the Outlook window. The set of folders cannot be opened” issue.

Microsoft Outlook is a popular email client. It is the most widely used application for managing emails for personal or professional purposes but sometimes users face some issues with it. One such issue is that The set of folders cannot be opened in Outlook. This is an unexpected error and stops users from opening Outlook and accessing their emails.

Why “Cannot Start Outlook. Cannot open the Outlook Window” error has occurred?

There are several reasons behind this issue which are given below-

• A corrupted Outlook profile may have caused Outlook to fail when trying to open folders.
• Faulty Add-ins can interfere with Outlook functionality and may cause The set of folders cannot opened. An unexpected error has occurred.
• Corrupted PST files can also prevent you from opening Outlook folders.
• Antivirus or other security software can conflict with Outlook, so you are not able to open folders in Outlook.

How to Fix The Set of Folders Cannot be opened. An unexpected error has occurred” Issue?

There are some possible solutions to solve “Cannot Start Microsoft Outlook. The set of folders cannot be opened” error.

1. Update Outlook

The outdated Outlook version may cause various issues including the “Cannot start Microsoft Outlook. Cannot open the Outlook window” error. So, ensure that there are no pending Outlook updates. To check it-

1. Open Outlook and click on the File tab.
2. Click on Office Accounts >> Office Update >> Update Options >> Update Now.

2. Disable Outlook Add-ins

Sometimes add-ins can conflict with Outlook functionality and slow down the performance of the Outlook application. If Add-ins is causing the error message that cannot open Outlook set of folders then try to disable them and check error is solved or not. Follow the below-given steps to disable add-ins in Outlook-

1. Open Outlook and click on File tab.
2. Go to Options and click on Add-ins.
3. Click on the COM Add-ins and uncheck the box next to Add-ins and then click OK.

After disabling all Add-ins restart Outlook and check whether the error is resolved or not.

3. Reduce PST File Size

Sometimes large PST file can stop Outlook from opening folders. So, compress your PST file by compacting it. To do this

1. Open Outlook and click on File >> Account Settings >> Account Settings.
2. Select PST file from Data Files tab and click on the Settings option.
3. Click on Compact Now to initiate the process.

4. Repair PST File

Outlook provides a built-in repair tool that is called Scanpst.exe to fix minor issues with the PST file. To do this-

1. Go to the location of ScanPST.exe on your system and run it.
2. Browse the file that you want to repair and click on the Start button to initiate the scanning process.
3. If scanning detects any issues with this file then click on the Repair option to repair the file.

5. Create a new Outlook Profile

A corrupted Outlook profile can also cause for not opening the set of Outlook folders issue. So, create a new Outlook profile and set it as default to configure your email account. To do this-

1. Open Control Panel and click on Mail.
2. Click on Show Profiles and then Add to create a new profile.
3. Follow the prompts to set up your email account and then launch Outlook using this profile and check error is solved or not.

6. Delete XML File from Outlook Directory

A corrupted XML file in the Outlook directory can stop Outlook from opening and may also cause the set of folders cannot be opened issues. Removing these files from Outlook directory can solve the issue. To do it-

1. Open Run window, type AppData and then press Enter.
2. AppData directory will appear when navigate to Local>> Microsft>> Outlook to open Outlok folders.
3. Remove the XML files from the folder and restart Outlook to check error is solved or not.

7. Reset Navigation Pane

The navigation pane in Outlook displays the folders and items in the mailbox. Sometimes customizations in the navigation pane can stop you from opening Outlook. You can reset the navigation pane to fix this issue. To do this-

1. Close all Outlook-related applications.
2. Press Windows + R to open Run tool.
3. Type outlook.exe/resetnavpane and press Enter.

After running this command open Outlook and check problem is solved or not.

Conclusion

In this write-up, we have discussed the best possible ways to fix “The set of folders cannot be opened. An unexpected error has occurred”All the different techniques are explained in detail. Find out the cause behind this issue and choose the solution according to reason.

Frequently Asked Questions

Q 1. How to fix the set of folders that cannot be opened error in Outlook?

Ans – Update Outlook, disable faulty Add-ins, temporarily disable antivirus software, repair corrupted PST file, reduce PST file size, repair Outlook profile, remove XML files from the Outlook directory, etc.

Q 2. How do I reset folders in Outlook.

Ans – To do it- Exit Outlook, run Outlook.exe/resetfolders >> run Outlook.exe/resetfoldernames.