Resolve the Outlook This is Not a Valid File Name Issue Quickly

Published by John on Last Updated On :

Outlook This is Not a Valid File Name

MS Outlook is a highly user-friendly application. You can easily manage your emails, and contacts and save various files. However, sometimes saving files doesn’t seem so easy. Users report encountering Outlook this is not a valid file name while trying to save or open a document. The error message further prompts them to examine the file path to ensure that it was typed accurately. Naturally, if you want to open a specific file urgently, the error message will be frustrating. But it is not that you cannot resolve it. In this guide, you will find different measures to resolve this technical problem.

Why Outlook This Is Not a Valid File Name Error Occurs

Before fixing this problem, you must look into the reasons causing it. Some prominent causes are as follows:

  • There’s invalid text data and hidden links in empty spaces.
  • There are broken images in the message’s body.
  • Your file name has certain symbols which are causing this error.
  • There are external add-ins that conflict with the application.
  • The Microsoft Office application is corrupt.
  • There is some issue with your current Outlook profile.

If you face Outlook folders not showing errors you can read this post.

Fixes to Use for the Invalid File Name Error in Outlook

Now that you know the culprits, you can troubleshoot them one by one. After each measure, see if the problem has been resolved.

Method 1: Examine the email’s body

It is essential to examine the body of the email whenever you face this specific error. There may be links that are broken or hidden links. Once you take away all these links from the body of the email, you will no longer encounter this error. To remove the links, you can turn HTML into Plain Text. This will resolve all problems with links.

Method 2: Check the characters in the file name.

The Outlook file name invalid issue occurs if you save a file with an invalid character in its name. Characters such as the ones below are not considered valid file names.

  • Less than sign (<)
  • Greater-than sign (>)
  • Backward and forward slash (\ /)
  • Pipe (|)
  • Colon (: )

If your file name has one or more of these characters, take it away from the name. After that, save the file. You can then open it to check if the error has been resolved.

Method 3: Review the Outlook plugins

Conflicting plugins or add-ins also result in users finding the Outlook cannot send this item problem. So, review the plugins with the steps below.

  • Head to ‘File’ in the Outlook application.
  • Now, go to ‘Options’ and after that, choose ‘Add-ins.’
  • You will find the list of add-ins.
  • Disable the ones you think are behind the issue.

Method 4: Use Safe Mode to run Outlook.

After disabling the add-ins, open Outlook in safe mode. Just open the Run dialog box by pressing Windows and R keys. Then enter Outlook.exe / Safe and press Enter.

If you notice Outlook working properly, it means the add-ins were causing the issue.

Method 5: Update and repair MS Office

It is essential to operate on the latest Office version on your computer. You can easily find if your Office app is recent by heading to ‘File.’ Once there, choose your account and tap ‘Update Now.’

By just updating MS Office, you will find an improvement in the situation. But if you find this is not a valid file name Outlook issue, it indicates that Office files are corrupt. Repair them through these points.

  • In the ‘Control Panel’ section, head to ‘Programs.’
  • Now, choose ‘Programs and Features.’
  • After that, select ‘Office 365.’ Some users may find this option as ‘Microsoft 365.’
  • Tap ‘Change.’
  • Now, pick the ‘Quick Repair’ option.
  • The error will go away after you choose this option.
  • But if it doesn’t, open the ‘Online Repair’ process.

Method 6: Delete the old Outlook profile.

Microsoft Outlook this is not a valid file name error also arises from issues in your Outlook profile. Creating a new profile will help you get rid of this error.

  • Head to ‘Control Panel’ on your system.
  • Once there, change the ‘View by’ mode. Modify it to ‘Large Icons.’
  • Now tap ‘Mail (Microsoft Outlook).’
  • After that, tap ‘Show Profiles.’
  • Choose the old profile you want and tap ‘Remove.’
  • Then tap ‘Yes.’
  • To make another profile, tap ‘Add.’
  • Now input the needed account data and abide by the guidelines on your screen.
  • When you are done, start Outlook again.

Sometimes,  Outlook certificate expired error occurs and you face many errors. Due to this you can not able to access Outlook application.

Method 7: Fix the error with the PST file’s path.

Problems with the path of PST files happen if you’ve modified the values in Outlook’s Registry Editor. It, in turn, leads to Outlook this is not a valid file name error. To resolve it, go through these points.

  • Launch the ‘Run’ dialog box.
  • In this box, input ‘regedit’ and press ‘OK.’ The Registry Editor will open.
  • To give permission to the prompt of ‘User Account Control,’ tap ‘Yes.’
  • Head to the following path: ‘HKEY_CURRENT_USER\Software \Microsoft \Windows \CurrentVersion \Explorer \User Shell Folders
  • Click twice on the ‘Personal’ string value.
  • Configure the ‘Value Data’ to ‘%USERPROFILE%\Documents’
  • Then tap ‘OK.’
  • Exit the Registry Editor and open Outlook again.

Method 8: Use the System Restore functionality.

If you’ve used all the techniques given above but still find this problem, use the System Restore feature. This functionality is there in the Windows operating system. It reverts the computer to a previous working state when Outlook would have been working without any glitches. However, note that using this feature will remove all the applications that you installed post the restore point date.

  • Opt for the ‘Start’ button in your system.
  • Input ‘Control Panel’ in the field and choose the application’s option from the results.
  • Now, look for the recovery option here.
  • Choose it, followed by ‘Open System Restore.’
  • After that, select ‘Next.’
  • Choose the restore point related to MS Outlook.
  • After that, select ‘Next.’
  • Then, tap ‘Finish.’

Final Thoughts

You can address Outlook this is not a valid file name error in several ways. Understand the causes and implement the corrective fixes. Use this guide whenever you face this problem. If you need more assistance, it’s best to speak to a professional email technical support expert.

Written By


John is a Technical Writer at Email Support, has 10 years of experience, and is an expert in Email and Cloud Computing. His specialty is writing about the Email clients such as Outlook, Yahoo, Verizon, SBCGlobal, Gmail, Apple Mail, AOL, WildBlue, and others.

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Categories: Outlook


John is a Technical Writer at Email Support, has 10 years of experience, and is an expert in Email and Cloud Computing. His specialty is writing about the Email clients such as Outlook, Yahoo, Verizon, SBCGlobal, Gmail, Apple Mail, AOL, WildBlue, and others.

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