Microsoft Outlook users have been facing a particular bug over the past decade. It started with Outlook 2010 and users of future versions continue to report about it, including Office 365. Users see a pop-up saying ‘Cannot expand folder’ error in Outlook. It happens when expanding a shared folder or a folder in a second mailbox.
It’s not clear how long this bug lasts, but Office 2019 users seem to be getting better. You might consider upgrading to that.
Let’s get started.
1. Folder Limit
Microsoft Outlook has a limit of 1000 folders. If you have more than the specified number of subfolders, the folder will not expand. That limit applies to Microsoft Exchange accounts. The folder limit is 500 for Outlook 2010, 2013, 2016 and 2019 versions. Additionally, the number of items per folder cannot exceed 100,000. Microsoft notes that you may experience performance issues if you violate the limits.
2. Disable add-in
Have you installed the add-in in your Microsoft Outlook account? One or more add-ins may be causing a conflict resulting in the Unable to expand folder error in Outlook. Open Outlook in Safe Mode to remove all add-in problems. You can also disable all add-ons without going into Safe Mode. If the error is gone, you will need to re-enable the plug-ins one by one to verify which plugin is responsible for the error.
3. Disable Cache Mode
Does it happen on an Exchange account or in a shared mailbox? If that’s the case, disabling cache mode can help fix the Unable to expand folder error in the Outlook app.
Click the File menu option.
Click Account Settings and select Account Settings from the drop-down menu.
You should see a list of all email accounts now. Double-clicking the email ID is causing the Unable to expand folder error.
Uncheck Use Cached Exchange Mode here and save the settings.
Turn it off, save the settings, close Outlook and launch it again to try again. Cache files can be the cause of the folder acting weird. Disabling cache mode will force Outlook to re-sync and download folders and messages again.
4. Fix Outlook App
Search for and open Control Panel from the Start menu.
Search for Uninstall in the Control Panel search and open Uninstall a program.
Look for the standalone Outlook app if you have it installed or the version of the Microsoft Office suite. Select it and click the Change button at the top.
You will see a pop-up with two options. Quick fix will work offline and fix the most common errors. Try that first. If it doesn’t work, try Online Repair.
That will take longer and requires an active internet connection. I recommend connecting the laptop to a Wi-Fi network and a power source.
5. Create a New Outlook Profile
You should follow point 4 above before proceeding to create a new profile. Rename a folder that you cannot expand in Outlook. Right-click on the folder and select the Rename option to do so. Take backups, if you must. If you backed up on the server or in the cloud, remove the configuration mentioned below:
C:\Users\USERNAME\AppData\Local\Microsoft\Outlook
Of course, the Username above and the drive letter should be the username and the drive of your respective Windows installation. Restart your computer.
Open Outlook and in the File menu, click Account Settings > Manage Profiles.
Click Show Profile.
Click Add to start creating a new profile.
You can now add an email account to this newly created profile and check if you still get the Unable to expand folder error.
6. Repair PST and OST . files
Outlook email account data is stored in a .PST file if you are using an IMAP or POP account. The same is stored in the .OST file if you are using an Office 365 or Exchange account. Depending on the email account causing the Unable to expand folder error in the Outlook app, choose a method.
Repair OST file
Open Control Panel and go to User Accounts > Mail > Show Profiles. Select the configuration you are having problems with and click Properties below. Now select Data File in the following pop-up window.
Select the email account data file and click Open file location.
A new window will open with the file name with the extension .OST. Delete the file and restart your computer. Launch Outlook and it will automatically regenerate the file.
Repair PST . files
The same steps will not work for .PST files. Press Windows key + R to open Run prompt. Enter the file path below in case of Office 2016, Office 2019 and Office 365.
C:\Program Files (x86)\Microsoft Office\root\Office16
For Outlook 2013:
C:\Program Files (x86)\Microsoft Office\Office15
Double-click the SCANPST.EXE file, which launches the Microsoft Outlook Inbox Repair experience. I wish there was a direct way to launch it.
Click Browse on the following pop-up.
A new File Explorer window will open. You need to locate the .PST file here and when you find it, click the Start button.
Select the option ‘Make a backup of scanned files before repair’ to create a backup in case something goes wrong.
Now click on Repair to start the process.
Take care
There are so many versions of Outlook that Microsoft has released over the years. That makes troubleshooting a bit more difficult. However, we do our best to offer the best possible solutions. If you have found another way to solve the Unable to open folder in Outlook app error, let us know in the comments section below.
Next: Using Microsoft Outlook on your smartphone? Here are 9 cool Outlook tips and tricks for Android and iOS.
Categories: How to
Source: thpttranhungdao.edu.vn/en/
