The attempt to log on to Microsoft Exchange has failed
Microsoft Outlook is a perfect app for sending and receiving emails and managing other personal data. But sometimes Outlook doesn’t open and gives the “Cannot start Microsoft Outlook…” error message. Show
It may seem daunting, but there’s no need to panic. You can easily fix this from your home by using the methods in this article.
There are many probable causes for this issue, and different messages accompany the “Cannot start Microsoft Outlook” error in individual cases. Some of the usual reasons include:
Fixes for Cannot Start Microsoft Outlook ErrorDepending on the cause of the error, there are several possible solutions. First, restart your computer and check if the error persists. If it does, move on to the fixes below: Open in Safe Mode and Disable Add-insIn many cases, this error occurs due to conflicts with Outlook Add-ins. You can check this easily by opening MS Outlook in safe mode. To do so:
If Outlook doesn’t open, then some other causes are responsible. So, move on to the subsequent solution. If you can successfully open Outlook, disable all Add-ins by following the steps below:
Restart Outlook in normal mode. Then re-enable an add-in and restart again. Do this for all options to determine the culprit. Disabling the responsible add-ins should fix this issue. Reset Navigation PaneCorruption of the Navigation Pane’s XML file is also another reason for Microsoft Outlook failing to start. The error message should also mention “invalid XML” in such cases. You can fix this issue by resetting the file. Here’s how you can do so:
Do this for all computers if you have more than one. Repair PST Data FileThere are many cases when the Outlook data files get corrupted and cause this error. The solution is to repair the files. Fortunately, Outlook includes a program to do just that. You can use either POP3 or IMAP to receive messages. While using IMAP, Outlook uses a If you use POP3, syncing is impossible, and Outlook will save all data on a local drive as a
If you want to know more about this process and what to do if you couldn’t recover all data, visit our article on How to Repair Outlook Data with the SCANPST.EXE tool. On Mac, data files have the Delete OST Data FileAs we mentioned in the previous method, you can delete the
Open MS Outlook and add the deleted account. It will recreate a You can also delete the Create New ProfileYou can also try creating a new profile to check if the previous one has become corrupt. To do so, On Windows:
On Mac:
If you can log in to the new profile in Outlook, the precious one has some errors. Back up the data from the old profile and remove it in such cases. Check Compatibility ModeIf Outlook is running in compatibility mode for old OS, it won’t work properly in newer versions. So, disable compatibility mode and check if this resolves the error. To do so,
Perform Clean BootThird-party applications are also known to mess with Microsoft Outlook, causing this error. A well-known offender is the Skype for Business application. Boot your PC in safe mode to check if there’s any interference due to third-party processes. If no error occurs in safe boot, restart your computer in normal mode and perform a clean boot to isolate the culprit. Then you can repair or uninstall them. Repair / Reinstall OfficeAnother solution you can try is to repair or reinstall Microsoft Office. We recommend this solution especially if other Office components also show errors. Here’s how you can do so:
Also, make sure to reinstall it using an administrator account. Update OS & Device DriversOutdated Operating Systems or Device Drivers can cause many system and application problems. Sometimes Outlook may fail to start due to issues with the system itself. We recommend updating them to the latest versions to troubleshoot the underlying bugs when you encounter this error. Recovery Assistant for Microsoft 365Microsoft provides a recovery assistant for Microsoft 365 to troubleshoot the Outlook not starting error. Download the file and run it if you encounter this problem in Microsoft 365. Disable Cached Exchange ModeIf an Office 365 account has two or more Microsoft Exchange accounts, this error may happen in a few cases. To fix this issue, you need to disable Cached Exchange Mode in all but one account. Here’s how you can do so:
Increase MAPI Session LimitBy default, Microsoft Exchange limits MAPI sessions to 40 clients. If you exceed this limit, you will get the message “Cannot start Microsoft Outlook…The attempt to log on to Microsoft Exchange Has failed”. Increasing the MAPI session limit should fix the issue. To do so,
Reinstall Outlook ConnectorIf the error message also displays “MAPI was unable to load the information service msncon.dll”, there’s an issue with the Outlook Connector. Reinstall it to debug the error. Related QuestionsOutlook Stuck on Loading Profile. How to Fix it?This mostly happens because of conflicts between your OS and OEM graphics drivers. However, there may also be other reasons. Check out our article on Outlook Stuck On Loading Profile to find out how to fix the problem. How to Fix Outlook Not Responding?We have a dedicated article on 13 Ways to Fix Outlook Not Responding. Check it out to find how you can troubleshoot this issue. What does the attempt to log on to Microsoft Exchange has failed?The attempt to log on to Microsoft Exchange has failed." One of the reasons could be the corrupted XML file in your Navigation settings. If you would like to go deeper, for this reason, make sure to check out the XML file size. If you see it as 0KB, it means it is the culprit why you cannot open Outlook.
Why can I not connect to Microsoft Exchange?Cause: Your account credentials or Exchange server name are incorrect. Solution: Verify your account settings. On the Tools menu, choose Accounts. In the left pane of the Accounts dialog box, select the account.
How do I fix Outlook The connection to Microsoft Exchange is unavailable?Method 1: Update or create your Outlook profile with RPC encryption. In Control Panel, open the Mail item.. Select Show Profiles.. Select your profile, and then click Properties.. Select E-mail Accounts.. Select Microsoft Exchange (send from this account by default) account > Change.. How do I reconnect Microsoft Exchange?On the web client and Desktop App, click your user name, and then click Settings. Click the Extensions tab. Locate the Microsoft Exchange extension, and then click Connect.. Username and password.. Windows authentication.. Office 365 Exchange.. |