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MS Outlook has become the to-go application for all professionals to prioritize all their email and data management needs. But it is also not immune to technical glitches. Many users have experienced trouble while opening certain PST folders. If you have similar issues where you cannot open or expand the folder in the Outlook application and do not get a way out of this, then reading this blog is a must for you.
We are going to explain the best solutions to fix this error and let you access the folder again to carry on with your work.
The error message that pops up is:
“Cannot expand the folder. The set of folders cannot be opened.“
This error is common in Outlook 2010 and later versions, to the extent that thousands of users have complained about it. It occurs when an Outlook user attempts to expand the shared folder, public folder, Address Book, or another secondary mailbox from the interface. Instead of expanding the respective folder, the error says:
“Cannot expand the folder. The Set of Folders cannot be opened. “
“Cannot expand the folder. Microsoft Outlook cannot access the specified folder.“
Let us know what reasons can be assumed for the occurrence of this error.
Reasons that are responsible for the “Cannot Expand the Folder” error
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Try these simple solutions to fix or resolve the “Cannot expand the folder” error on your own.
Solution 1: Make the folder “Visible”
Solution 2: Disable the cached mode
Solution 3: Disable Microsoft Outlook Add-ins
Solution 4: Create a new Outlook profile
Solution 5: Repair the Outlook application
Solution 6: Repair the Outlook database files
Solution 7: Using the Microsoft Support & Recovery Assistant (MSRA) Tool
Here is the complete explanation of the above-mentioned solutions with their entire process.
First, make sure that there are more subfolders than the limit. Earlier, the limit was 5000, but later, Microsoft increased the folder limit. Now, 5000 items per calendar folder and 100000 items per folder are allowed. Then check if the permission for the .Ost folder view is assigned or not.
Cached Exchange Mode saves a copy of the mailbox to the user’s computer, and this enables easy access to all the data. But when this mode is on, it may cause trouble in expanding the respective folder due to synchronization issues. It is suggested to disable the cached Exchange mode in Outlook in such a situation. Follow this process to do so-
Conflicts with the third-party add-ins can affect the synchronization of the mailbox as well as the functioning of the application since they become roadblocks to a smoothly running function. Running the application in the Safe Mode might also help to resolve the issue. You can also try disabling the Outlook add-ins using the following procedure and then attempt to expand the problematic account folder.
Due to some bugs, errors, or other issues, the application may also get corrupted. Taking it as a solid reason behind this issue, you can try performing an online repair on your Microsoft Office application suite. But before you begin with it, make sure you have a strong network speed to perform this repair. The procedure is as follows-
A corrupt Outlook profile is another major cause of many problems in Outlook, including this one. All Outlook users can anytime create a new Outlook profile and set it as the default one.This will give you a clean start, and the corruption-containing profile will be deleted for good.
Perform these steps to create a new Outlook profile-
The corrupt .ost file can be a reason for the error, but here you have an advantage that you can anytime recreate the OST file of your configured Exchange Server account. You just require opening the .ost file location from the Account Settings in Outlook and then deleting the problematic .ost file from there using the Delete option simply.
The default location of the Microsoft Outlook .ost file is given as:
Then restarting the Outlook once would recreate a fresh .ost file without issues. It can resolve your issue if corrupt .ost is the problem.
For users who have corrupted or orphaned .ost files, we recommend the most efficient and secure Kernel OST to PST Converter, which readily recovers data from the corrupt, damaged, or orphaned offline .ost file and allows to save it to the PST file format and more destinations. This tool is suitable for all users, including beginners, and it will get the work done in a jiffy.Get complete information about the tool by visiting its official website.
To resolve the “Outlook cannot expand the folder” error in Microsoft Office applications, you need to download & install the Microsoft Support & Recovery Assistant (MSRA) tool on the affected system.
Microsoft Outlook allows you to create 1000 folders. If the number of subfolders exceeds the specified number, the folder will not expand. The limit is applicable to Microsoft Exchange accounts. There is a 500 folder limit for Outlook 2010, 2013, 2016, and 2019. In addition, no folder can contain more than 100,000 items. You might face performance issues in case these limits are exceeded. So, make sure you are within these prescribed limits.
To fix the “Cannot Expand the Folder” error, users must make sure that their mailbox is properly synced and configured with the necessary settings. If the issue persists, it could be due to corrupt or damaged OST files. In such cases, using a reliable OST to PST converter like Kernel for OST to PST is highly recommended. This efficient tool can easily convert OST files to PST without any issues with the integrity of user data. So, don’t let the error hamper your work efficiency and opt for this beneficial solution now.
A- This error message indicates that there is not enough memory available to perform the operation, which can be caused due to different factors. It could be due to an issue with Outlook, or your computer is running low on memory and storage space.
A- In Microsoft Outlook versions from 2010 to 2021 and Microsoft 365, the size limit for Outlook folders is set to 50GB. But it is not recommended to exceed this limit due to potential performance concerns.