How to Fix Outlook cannot open the set of folders Error

Imagine you click on the Outlook icon and instead of seeing your inbox you get a frustrating pop-up saying that Outlook cannot open the set of folders. This happens when Outlook cannot communicate with its data file or the settings are broken. You do not have to be a computer expert to fix this as this issue is caused by a simple setting that got stuck or a file that needs a quick repair.

You can clear this issue by resetting the navigation pane or creating a new profile in just a few minutes. Today we will look at the most effective ways to get your emails back and recover everything from simple command-line to repairing your data files. We will also show you how to use a professional tool like the Sys Tools OST to PST Converter Tool to save your data if your files are badly damaged.

Why does Outlook say it cannot open the set of folders?

Before looking at the steps, let’s understand why Outlook cannot open the set of folders. When you see this message it generally points to one of the following things:

1. Navigation Pane Issues: The settings that control your folder list on the left side of the screen are damaged.
2. Compatibility Mode: Outlook is trying to run as if it were on an older version of Windows.
3. Broken Data Files: The OST or PST file where your emails live is damaged.

Method 1: Reset the Navigation Pane

The most common reason for the Outlook cannot open the set of folders message is a glitch in the XML file that stores your navigation settings. Sometimes resetting this is the only step that you need. In this method Outlook will now open and rebuild your folder list settings from scratch. Look at the following steps to reset the pane:

1. 1. First close Microsoft Outlook completely.
   2. Press the Windows Key + R on your keyboard to open the Run box.

• Then type the following command: outlook.exe /resetnavpane.

1. Finally click OK or press Enter.

Method 2: Turn Off Compatibility Mode

If you have recently updated Windows then Outlook might be running in Compatibility Mode. This generally triggers the Outlook cannot open the set of folders error. Use the steps mentioned below to turn off this mode:

1. Find the Outlook icon on your desktop or in the Start menu.
2. Right-click the icon and select Properties.
3. Then go to the Compatibility tab.
4. Look for the box that says Run this program in compatibility mode for.
5. If it is checked then uncheck it.
6. Finally click Apply and then OK.

Note: You can also import OST to Outlook Classic and New Outlook for Windows using very simple steps. If you want to know about it, do give it a read.

Method 3: Fix Corrupted Data Files with an Expert Tool

If your OST file is corrupted the your email account will not load and this is the main reason why Outlook cannot open the set of folders. You can lose data that has not been connected to the server if you try to delete the OST file.

The expert solution is effective as it is designed to read damaged OST files and move your emails, contacts and calendars to a healthy PST file that Outlook can open easily.  

Why choose this Tool?

1. Ability to work with very large files without crashing.
2. Your folders and subfolders stay where they were.
3. It recovers emails, attachments and even deleted items.
4. Handle files that the normal Windows repair tools cannot handle.

Steps to use this Tool:

1. Download and open the tool.
2. Click on Add File and select the OST file that is causing the problem.
3. Then let the tool scan the file for errors.
4. You will see a preview of all your emails. Select PST as the export format and click on Export.
5. Finally you can open this new PST file in Outlook and the error will be gone.

Method 4: Create a New Outlook Profile

Your entire Microsoft Outlook may be broken if the above methods do not work. Creating a new one is a great way to fix the Outlook cannot open the set of folders error. Follow these steps to create a new profile:

1. First open the Control Panel on your computer.
2. Search for Mail and click on it.
3. Click on the Show Profiles button.
4. Press the Add button and give the new profile a name.
5. Follow the prompts to add your email account.
6. Select your new profile under the section Always use this profile.
7. Click OK and restart Outlook.

Summary

We have learned that Outlook cannot open the set of folders message is generally a sign of a small error rather than a serious issue. We started by resetting the navigation pane which fixes the majority of cases where Outlook could not open the set of folders. We also looked at how compatibility settings can interfere with your mail.

If those simple methods do not work then we explained that the problem may lie in your data files. Using a specialized tool is an effective way to handle situations where Outlook cannot open the set of folders error is caused by deep file corruption. Finally we showed how creating a new profile can give you a new start. You can ensure your emails are safe and your Outlook stays reliable by following these steps.