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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 the explain the best solutions to fix this error and let you access the folder again to carry on with your work.
The error statement that appears while experiencing this error to access the account mailbox folder is like this-
“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
Here is the complete explanation of the above-mentioned solutions with their entire process.
Make the folder “Visible”
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.
Disable the Cached Mode
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-
Disable Microsoft Outlook add-ins
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.
Repair the Outlook application
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-
Create a new Outlook profile
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-
Repair the Outlook Database File
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.
The error “Cannot Expand the folder” has been witnessed by many Outlook users. The causes behind this might be a lot but can also be resolved without any complications. To begin with, make sure the folders are visible and within the limit range. Then, disable all the add-ins as well as the Cached Mode. A heavily corrupted Outlook profile could be starting other issues as well; hence you can immediately create a new one. In case of corruption in the application or its files, users can always choose to repair those. To get the OST files accurately repaired, you can opt for a professional utility.