If you have issues like 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 attempting 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; it occurs when the 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 saying:
“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 can be responsible for the “Cannot Expand the Folder” error
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 are the complete explanation of the above-mentioned solutions with steps.
Make the folder “Visible”
First, make sure that there are more subfolders than the limit, i.e., maximum 500. Then check if the permission for the .ost folder view is assigned or not.
Disable the Cached Mode
When the Exchange cached 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.
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. You can 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 an assumption, you can try performing an online repair on your Microsoft Office application suite. Make sure you have a strong network speed to perform this repair. The procedure is as follows.
Create a new Outlook profile
The corrupt Outlook profile is another issue and could be a cause for this error. Outlook users can anytime create a new Outlook profile and set it as the default one.
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 of your configured Exchange Server account. You just require opening the .ost file location from the Account Settings in Outlook and then delete the problematic .ost file from there using the Delete option simply.
The default location of the Microsoft Outlook .ost file is given as:
Then on 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. Get complete information about the tool by visiting its official website.