Cannot expand the folder. the set of folders cannot be opened. your server administrator

Users are getting te following msg:

Your server administrator has limited the number of items you can open simultaneously. Try closing messages you have opened or removing attachments and images from unsent messages you are composing

and in exchange events I see : MAPI session (user) exceeded the maximum of 250 objects of type "objmessage".

I found this

https://www-secure.symantec.com/connect/forums/your-server-administrastor-has-limited-number-items-you-can-open-simultaneously

but the links are broken and they are saying that there is a fix for 9.0.1.

We have version 10.0.4 (clean installation, not upgrade)

Any ideas?

Sarah 

I recently had the experience of migrating a client to Office 365. While most things went smooth, one user who was using Outlook 2007 wasn’t able to open one of the shared mailboxes. Every time she tried to open the file, the following error message would appear:

[callout] Cannot expand the folder. The set of folders cannot be opened. Microsoft exchange is not available. Either there are network problems or the exchange computer is down for maintenance.[/callout]

I tried removing her profile and rebuilding it again, but to no avail. I was able to open the inbox using Outlooks option of File > Open & Export > Other Users Folder. I was also able to open the mailbox it in OWA.

In the end, the problem was related to the AutoMapping function of Exchange and Outlook. To solve the problem I had to do the following things:

1. Connect to O365 using your usual Powershell Connection lines:

$LiveCred = Get-Credential $Session = New-PSSession -ConfigurationName Microsoft.Exchange -ConnectionUri https://ps.outlook.com/powershell/ -Credential $LiveCred -Authentication Basic -AllowRedirection Import-PSSession $Session

2. Remove FullAccess permissions for the affected user from the shared mailbox

Remove-MailboxPermission (SharedMailbox) -User (UserAccount) -AccessRights FullAccess

3. Add Full Access permissions back on, but make sure you set AutoMapping to FALSE!

Add-MailboxPermission (SharedMailbox) -User (UserAccount) -AccessRights FullAccess -AutoMapping $false

4. Use Outlook to add another user’s mailbox by editing the account and adding the user by choosing (in Outlook 2013) File > Account Settings > Change > More Settings > Advanced > Add. The dialogue should look like below. Simply add the user’s in the Add dialogue and you should be good to go!

The error “The set of folders cannot be opened“ in Outlook has become quite a common issue. Unfortunately, many users of Outlook 365, 2016, 2013, and 2010 have encountered this Outlook error. This situation can be very frustrating as the error usually pops up out of nowhere stopping you from launching Outlook.

User Query: I tried to launch Outlook but I got an error message instead: "Cannot start Microsoft Outlook. Cannot open the Outlook Window. The set of folders cannot be opened. The attempt to log on to Microsoft Exchange has failed." How to fix this issue?

Whenever you encounter the above-mentioned error the Outlook application will fail to open. Even after launching the Outlook application multiple times, you’ll only see the cursor loading for a while, and after that, the error saying Outlook the set of folders cannot be opened will appear. 

Why Can’t Access my Folders in Outlook? 

The exact reason behind the error “Cannot start Microsoft Outlook. Cannot open the Outlook window. The set of folders cannot be opened” is uncertain. However, we can say that it mostly occurs because of Outlook data file corruption or if the .xml file with your Outlook name is damaged.

Other than the above-mentioned scenarios, it can also occur when you are running Outlook in Compatibility mode, or while using an Outlook profile that was created in an old version of Outlook. Other than this, incorrect installation of Outlook is one reason to encounter this error.

The reason behind such corruption can be many like virus infection, system crash, the system is powered down without closing Outlook, or even power failure. In the next segment, you will get to know how to troubleshoot this error. This will definitely help you in restoring Outlook, no matter what caused the error.

Before following the below-mentioned solutions, it is recommended to take a backup of the Outlook data files. 

Note: In case you didn’t know, Remo Outlook Backup and Migrate is an amazing tool that lets you automate your Outlook backup process, and also comes in handy during Outlook migration. Do check this tool 

Please ensure that you are running your system as an administrator. Also, you should close the Outlook application as the methods might not work if Outlook is running in the background.

Following are a few effective solutions to fix the error “Outlook the set of folders cannot be opened” are as follows:

1. Launch Outlook in Safe Mode
2. Update the Outlook application
3. Recreate your Outlook Profile
4. Turn off Compatibility mode in Outlook
5. Repair Office Installation
6. Fix Outlook
7. Repair PST Using ScanPST Tool
8. Fix PST File using Remo PST Repair
9. Disable your account from the Mail app
10. Start Outlook from the Taskbar
11. Delete XML Files from the Directory
12. Reset Navigation Pane
13. Reinstall Outlook

Solution 1: Launch Outlook App in Safe Mode

Running Microsoft Outlook in safe mode will not resolve the error “the set of folders cannot be opened” but you will get to know if the issue is with the Outlook application or the add-ins. Follow the below-mentioned steps:

1: Go to Start and open the Run application and type in ‘Outlook/safe’ and then the Enter key.

2: Next, choose your Outlook profile and enter your Outlook credentials if asked.

3: After this MS Outlook will start working in Safe Mode. 

After running Outlook in safe mode if it starts to work fine without any error, then the issue is probably with the add-ins. You  have to disable the add-ins to resolve the error “The set of folders cannot be found.”

1: To disable add-ins, go to File > Options 

2: Next, go to the Add-ins tab and select Com Add-ins from the drop-down menu. Then select the Manage > Go.

3: Uncheck all the add-ins displayed and click the OK button.

4: Now, verify if Outlook is running fine. Restart Outlook in normal mode and test.

Solution 2: Update Outlook Application

Check if there are any pending updates for the Office application. 

1: Go to File and select Office Account

2: Then go to the Office Update. 

3: Click on Update Options

4: Hit the Update now option to update the Outlook email client.

Solution 3: Recreate Your Outlook Profile

If updating the Outlook application was not able to fix the error in Outlook “the set of folders cannot be opened” then you have to recreate the Outlook email profile. This method has helped many users to fix the error. 

1: Go to the Windows search bar and type regedit. This will launch the Registry Editor.

2: Then, navigate to Computer\HKEY_CURRENT_USER\SOFTWARE\Microsoft\Office\16.0\Outlook\Profiles (Outlook 2019,2016)

3: Now delete all the folders listed under Profiles.

Note: If you are using a different version of Outlook this will change as follows. Computer\HKEY_CURRENT_USER\SOFTWARE\Microsoft\Office\15.

4: Relaunch Outlook and recreate your email profile.

5: Go to File > Account Settings > Manage Profiles

6: Click on Show Profiles and select the Add button.

7: Enter all the necessary details and save the changes.

8: However, it is not necessary to use the Registry Editor. Just follow the steps from 5 to 8 to create a new Outlook profile.

If you are unable to create a new Outlook profile using Outlook, you can make use of the Control Panel. Just go to Control Panel > Mail > Show Profiles > Add.

Note: In case of a corrupt or damaged Outlook profile, it is highly recommended to repair the corrupt Outlook profile.

Solution 4: Turn off Compatibility mode in Outlook

It has been noticed and reported by a few users that running Outlook in Compatibility mode can cause issues like “The set of folders Cannot be opened” in Outlook. Follow the below-mentioned steps to turn off the Compatibility mode in Outlook.

1: Open File Explorer and navigate to the folder where you have installed Office. By default, the folder can be found in the C drive. The path is: C:\Program Files\Microsoft Office\(Office version)

2: Right-click on Outlook.exe and select Properties 

3: Select the Compatibility tab and uncheck the box saying “Run this program in compatibility mode”.

4: Click on Apply, then exit by pressing OK.

5: Then launch Outlook again to see if the error still persists.

Solution 5: Repair Office Installation

1: Go to the Control Panel and select Programs.

3: Click on Change and launch the Quick Repair tool.

You should also repair the Outlook application for repairing Office could not fix the issue “cannot start Microsoft Outlook set of folders”.

Solution 6: Fix Outlook

1: Go to Settings and select Apps.

2: Select the Apps and Features option and navigate to Outlook from the list.

3: Click on Advanced options and select the Repair option.

If none of the manual methods were able to rescue you from the situation then it is recommended to repair the Outlook data file (.pst) file directly. For repairing the PST file you have two alternatives. One is using Outlook’s inbox repair tool(ScanPST Tool)  to fix the damage in the data file or an automated tool to repair the PST file efficiently. 

Solution 7: Repair the PST file using ScanPST Tool

1: Close Outlook if running in the background. Then navigate to Outlook 2016/2019: C:\Program Files (x86)\Microsoft Office\root\Office16 or Outlook 2013: C:\Program Files (x86)\Microsoft Office\Office15 (depending on your Office version).

2: Locate and run SCANPST.EXE.

3: Hit the Browse option to select the required Outlook Data File (.pst).

4: Click on the Start button and then select Repair

After repairing the PST file using the ScanPST tool, you have to create a new PST file.  Once you create a new Outlook PST file, you can just import the recovered Outlook items from Lost and Found or Recovered Personal Folders to your specified location.

This solution might help you in getting rid of the error and smoothly open the Outlook data file. However, if not then follow the next solution. 

Solution 8: Repair PST File with Remo PST Repair

You cannot always rely on the Inbox Repair Tool as it can only fix minor issues with the PST file. Additionally, one of the major disadvantages of using the Inbox repair tool is that you need to run it multiple times to repair PST files. Severely damaged data files cannot be fixed by Scanpst. Remo Repair PST tool will come in handy in such scenarios.

Choose the Remo Repair PST tool to repair PST files with any extent of corruption efficiently. Remo PST Repair tool is capable of safely repairing damaged, corrupt, and inaccessible PST files as it is equipped with advanced file repair algorithms.

• The tool is very easy to use and can repair the PST file in just 3 clicks. 
• Moreover, it is a read-only mode software that keeps your Outlook data safe. 
• Compatible with all the versions of Outlook including Outlook 2019, 2016, and its previous versions. 
• It not only fixes the damage in the PST file but also recovers missing Outlook items such as emails, attachments, contacts, folder structure, and rules.
• Watch the Video to Repair PST file. 

Note: Is your Outlook stuck at processing? Click on the link to know how to fix this error.  

Solution 9: Disable your Account from the Mail App

1: Go to the Control panel and search for Mail on the right top search bar. Then open the Mail app and click on Account Settings.

2: Select Manage Account and then select your Email Account 

3: Next, hit the Delete Account option 

4: Close the confirmation message and restart your PC. 

This method might help you in removing the error message “the set of folders cannot be opened”.

Solution 10: Start Outlook from the Taskbar

The Outlook error ‘The set of folders cannot open Outlook’ can be avoided by starting the Outlook from the Taskbar. It is a very simple solution as you just have to make sure that MS Outlook is pinned to the Taskbar on your system.

• If the Outlook app is not pinned to Taskbar, then find the Outlook shortcut on your system and drag it to the Taskbar. 
• Next, right-click on the Outlook shortcut in the Taskbar and select ‘New Email Message’ from the menu.
  
  

  This will make Outlook launch properly without any issues. However, this is just a workaround. This troubleshooting will not fix the error permanently. You will have to repeat the process every time you want to access Outlook.

• Try other methods to fix the issue as this is just a temporary fix.

Solution 11: Deleting XML Files from the Directory

Having an XML file in the Outlook directory could be another reason behind ‘the set of folders cannot being opened in the Outlook error. And if these files get damaged, it might stop Outlook from opening.

1: Go to Start and open the Run application

2: Type App data there and hit the Enter key

3: Next, the AppData directory will appear on the screen. You have to now navigate to LocalMicrosoftOutlook16*. (Change 16 with the Outlook version you are using)

4: Find the XML files and then either relocate or delete them.

After removing the .xml files, restart Outlook. Hopefully, this method might fix the issue and you face this error again.

Solution 12: Reset The Navigation Pane

The navigation pane consists of all the folders of your Outlook data files and icons like Calendar, Contacts, People, and Tasks. Sometimes, resetting the navigation pane might fix the issue of “the set of folders cannot be opened” in Outlook as this method will remove all the customization of the navigation pane that was existing in Outlook. To reset the navigation pane in Outlook, follow the below-mentioned steps:

1: First, close all applications related to Outlook.

2: Then open the Run application by pressing “Windows + R”.

3: Then type “outlook.exe /resetnavpane” and hit Enter.

Now again launch Outlook and check if it is running smoothly now. If the issue is not gone then reinstall the Outlook application. Make sure to take a backup before reinstalling the app.

Solution 13: Reinstall Outlook

Uninstall the Outlook application from your desktop  Then download Outlook again. This time Install the 64-bit version of Office. And mostly it is seen that the "set of folders cannot be opened" error appears in the 32-bit version.

If the error persists, go to Control Panel and select Uninstall a program. Then uninstall your Office app. After this, restart your system and reinstall Office. Check if the error  “the set of folders cannot be opened” in Outlook 2016 is solved now.

Conclusion

Hopefully, after following the manual methods you are able to fix the issue with Outlook “the set of folders cannot be opened”. However, if you are still struggling to fix the PST file error then use Remo Repair PST Tool. It can fix all kinds of errors related to the PST file and also helps you recover Outlook PST data. 

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