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Cannot Start Microsoft Outlook Invalid XML – Solved

  Rollins Duke
Rollins Duke   
Published: August 1st, 2025 • 7 Min Read

Microsoft Outlook is too popular for sending and receiving emails for personal and corporate purposes. However, Many users face issues Cannot Start Microsoft Outlook invalid XML a pop up error message says Cannot open Outlook Window. The XML file is not valid.

This Invalid XML error in Outlook prevents the applications from launching entirely, disrupting access to emails, calendar entries, and other data. If you are here then you are also facing the same error. This guide will share reasons behind this error and also explain the most effective methods to fix it quickly and safely.
Invalid XML Error
Cannot Start Microsoft Outlook Invalid XML error mostly happens due to Navigation Pane Settings as its Outlook XML file stores all navigation data such as layout and Outlook interface customization. If it becomes corrupted or stores mailformed XML code, Outlook fails to load the interface correctly, resulting in the error.

Table of Content Hide
  1. Why Does “Cannot Start Microsoft Outlook Invalid XML” Occur?
  2. How to Verify That the Outlook XML File Is Corrupted?
  3. Alternative Approach to Fix Cannot Start Microsoft Outlook Invalid XML Error
  4. Preventive Measures & Best Practices
  5. Conclusion

Why Does “Cannot Start Microsoft Outlook Invalid XML” Occur?

  • Outlook stores the layout of your interface including folder pane position and open windows in a file named Outlook.xml. If this file becomes damaged or contains malformed XML code, Outlook may be unable to launch properly. This is one of the prime reasons for Cannot Start Outlook Invalid XML.
  • Outlook files store emails, contacts, calendar and all Outlook data. If these file become damaged due to unexpected shutdown or storage issues Outlook hangs on loading profile.
  • Running Outlook in compatibility can interfere with its functionality and customization and due to these Cannot Start Microsoft Outlook.
  • Using an outdated version of Outlook or one no longer supported by Microsoft can result in compatibility issues with Windows or Office components. These issues may corrupt XML settings or prevent Outlook from reading them correctly.
  • A corrupted Outlook profile can also lead to startup problems, including invalid XML error. The user profile contains essential configuration settings, and if these files become corrupted. Outlook cannot start or not load the navigation pane or other startup components.

How to Verify That the Outlook XML File Is Corrupted?

Before attempting to fix the Cannot Start Microsoft Outlook Invalid XML error you need to check the issue happening with your Outlook.xml file. This file stores the navigation pane layout and can sometimes become unreadable or empty.

  1. You can manually navigate to the Outlook.XML file: C:\Users\\AppData\Roaming\Microsoft\Outlook\.
  2. Right-click on file and press on Properties.
    Click on file
  3. Check the size and tap on if it shows 0 KB, then the file is likely empty or corrupt.
  4. Review the Modified date or an old or usually recent timestamp.
  5. Right-click on file and tap on open with and choose Notepad.
  6. If the file appears blank or not in the standard XML structure then it’s almost corrupted.

Fix1: Reset Outlook Navigation Pane

  1. Press Win+R and type Outlook.exe/resetnavpane.
    Outlook.exe /resetnavpane
  2. Outlook should now launch without using corrupted navigation settings.
    Launch Outlook without using navigation pane

Fix2: Delete the Corrupted Outlook XML File

  1. Navigate to Outlook XML path: %appdata%\Microsoft\Outlook\Outlook.xml.
  2. Delete it or rename it as old.xml as per required.

Fix3: Disable Compatibility Mode for Outlook.exe

  1. Navigate to the Outlook installation folder(usually in C:\Program Files\Microsoft\Office\root\Office16 as per your version.
  2. Right-click on Outlook.exe and choose Properties.
    Click on Properties
  3. Navigate to compatibility mode and uncheck Run this program compatibility mode for.
    Uncheck Run this Program compatibility mode for
  4. Click on Apply and relaunch Outlook to verify.
    Relaunch Outlook

Fix4: Run Outlook in Safe Mode and Disable Problematic Add‑ins

  1. First open Task Manager and close Outlook completely.
  2. Press Win+R and type Outlook.exe/safe.
    Type Outlook.exe/safe
  3. Go to file and press on options.
    Click on options
  4. Hit on Add-ins and select Manage COM:Add-ins.
    Click on Add-ins
  5. Press on the Go button and disable faulty add-ins.
    remove faulty add-ins
  6. Relaunch Outlook to verify Cannot Start Microsoft Outlook invalid XML error solved.
    Open Outlook

Fix5: Repair Corrupted PST/OST via SCANPST / Inbox Repair Tool

  1. Navigate to: C:\Program Files\Microsoft Office\root\Office16\ScanPST.exe.
  2. Launch ScanPST Tool and click on the browse icon to add Outlook files.
    Choose Outlook files
  3. Hit on the Repair button to recover Outlook files.
    Click on Repair

Fix6: Restore Previous Versions of Outlook Files or PST Folder

  1. Right-click on Outlook data file folder or Outlook.xml.
  2. Select Properties and previous versions tab.
  3. Choose a version from before the issue occurred.
  4. Tap on Restore.

Fix7: Create a Fresh Outlook Profile

  1. Click on the Control Panel and tap on Mail(Microsoft Outlook).
    Tap on Mail(Microsoft Outlook)
  2. Tap on Add and name your new Outlook profile.
    Click on Add
  3. Setup email account and choose Prompt for a profile to be used and select your new profile.
  4. Launch Outlook with a new profile.
    Launch Outlook
Fix8: Update or Repair Microsoft Outlook / Office Installation
  1. Open Outlook and navigate to the file.
    Click on file
  2. Click on Office Account and hit on Update Options.
    Click on Update options
  3. Press on Update Now.
Alternative Approach to Fix Cannot Start Microsoft Outlook Invalid XML Error

If you want to fix Cannot Start Microsoft Outlook Invalid XML Error then we recommend you to choose BitRecover PST Repair Tool to recover Outlook files and a completely reliable utility to fix this error. To use this you just need to click on the download button and follow the procedure as we have discussed in the upcoming section.

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Steps to Fix Cannot Start Microsoft Outlook Invalid XML
  1. Download and run Expert Recommended Software on your machine.
    Launch Cannot Start Microsoft Outlook Invalid XML fixer
  2. Click on Select files or folders to browse Outlook files and tap on Next button.
    Browse Outlook files
  3. Preview Outlook folders as you wish to repair and again press Next.
    Select Outlook folders
  4. Choose the Saving option and destination path according to need.
    Select saving options
  5. Hit on Repair to fix Cannot Start Microsoft Outlook Invalid XML error.
    Cannot Start Microsoft Outlook Invalid XML solved
Useful Features of Expert Recommended Software
  • This tool can easily repair unlimited Outlook files at one shot without facing any limitations.
  • It is specially created with a simple initiative interface to make it easier to handle by all types of professional and beginner users.
  • You can also easily repair Outlook files without the scanpst tool.
  • It supports dual mode to select files or a whole folder of Outlook files to repair.
  • You can also repair and export specific folders from Outlook files without facing any restrictions.
Preventive Measures & Best Practices
  • Always use updated Outlook and Windows to get higher performance and fix bugs to maintain compatibility with your system.
  • Do not run in Compatibility mode without requirement. It can interfere with Outlook configuration files like Outlook.xml.
  • Before making any changes to your Outlook and Windows, take a backup Outlook.xml file located at: %appdata%\Microsoft\Outlook\.
  • Regularly backup your Outlook data files to avoid losing emails if corruption occurs. Use Outlook export feature to get backup files.
  • Before updating Outlook or Windows, create a system restore point to roll back in case of something wrong.
Conclusion

Now it’s time to conclude this article, as we have explained all the crucial information to successfully fix the “Cannot Start Microsoft Outlook Invalid XML” error. We have shared 9 tried and tested methods to solve “Cannot Start Outlook Invalid XML” both natively and through alternative approaches. The manual approach has no assurance of fixing this error. So, we suggest you choose expert-recommended software, as Outlook files contain all data. After recovery, this error will definitely be resolved, and you can also stay away from this error in the future.


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