Outlook cannot start

Question

So I am getting the [cannot start Microsoft Outlook. Cannot open the outlook window. The set of folders cannot be opened. An unexpected error has occurred] message

I have deleted and reinstalled office twice
Deleted the windows account and re added it [its an azure account so came back exactly as deleted]
Deleted Appdata both local and romaing for outlook

Any advice greatly apprecaited.

Answer 1

Hi @Clive ,

Welcome to our forum!

In order to verify your issue, does this issue only happen to a certain account? Have you tried open other profile?

So given this case, it is recommeded you use the following troubleshooting:

• First, you can downlaoad Support and Recovery Assistant for Microsoft 365 to diagnose and fix several common Outlook issues.
• To verify if it is related to some third-party add-ins, run Outlook in safe mode: Press Win+R, type outlook /safe in run command.
  If Outlook does start in safe mode, then the problem is likely with one of your add-ins. You'll need to disable all of your add-ins before restarting Outlook.
• Create a new profile via Control Pane > Mail > Show profiles > Add, type a new profile name, then re-add your account to test.
  
  

  ---

If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment". 
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.

Answer 2

The error “Cannot start Microsoft Outlook. Cannot open the Outlook window. The set of folders cannot be opened.” is one of the most common Outlook errors. It’s because this error prevents you from accessing your mailbox. You can quickly fix this error by applying below mentioned methods.

• Run Outlook in Safe Mode
• Update Outlook
• Remove XML Files
• Reset Navigation Pane
• Reduce Outlook Data File Size
• Repair Outlook Data Files

If a corrupt PST file causes the error, then you can use ScanPST or a third-party Outlook Repair Tool to repair the data file and fix the problem. For more information, you can check this Video: https://www.youtube.com/watch?v=AILCu8gmmt8

If the reply helped you, please remember to accept as answer.
If no, please reply and tell us the current situation in order to provide further help.