Sometimes, when you try to open a Word file it fails to open and displays the following message – Word cannot open the file because the file format does not match the file extension. This can be troubling, especially when you want to go through the contents of the file for one last time before sending it to someone else.

Word cannot open the file because the file format does not match the file extension

Word cannot open the file because the file format does not match the file extension

The problem can occur when the Word file you are trying to open has a different file extension than the file you are attaching. It happens when you convert the file manually. There can be other reasons as well. Whatever the case is, you can fix it by using any of the methods described below.

  1. Rename and change the extension manually.
  2. Change the file type to .asd.
  3. Uncheck Hide Extensions by known File Types
  4. Unlocking the Word file

Let us cover the above methods in a bit more detail!

1] Rename and change the extension manually

The simplest method to resolve this issue is to change the extension for the file manually. To do so, right-click the file and select Rename option.

Rename Extension

Then, change the extension of the document from *.docx to *.doc and then try opening the file. If this doesn’t fix your problem, move to the next method.

2] Change the file type to .asd

Go to the location where the file is stored, right-click it, and select the Copy option.

Then, move to the following path –  C:\Users%username%\AppData\Local\Microsoft\Office\UnsavedFiles by pasting this in the start menu.

Change File Type ASD

Paste the document here, and change the file type to .asd.

Recover Unsaved Documents

Open word, click Open, and at the bottom of the page hit the Recover Unsaved Documents tab.

When the document appears in the list, select it and save the document after opening it.

3] Uncheck Hide Extensions by known File Types

View Options

Open the File Explorer and go to the View tab. Just adjacent to it, you should find the See more icon visible as three horizontal dots. Click the icon and then, select Options.

Hide File Extension Types

When a new window appears, scroll down to locate Hide Extensions by known File Types entry. Make sure, the box next to it is left unchecked.

4] Unlocking the Word file

Many users reported that the issue ‘File format does not match the extension could also be resolved by unlocking the file. So, if you are not able to open the file sent as an attachment, use this workaround.

  • Open File Explorer.
  • Go to the path to the folder containing the Word file you want to fix.
  • Right-click on the file and choose the Properties option.
  • In the window that appears, switch to the General tab.
  • Find the Unblock button and click to select it. Note – This option is only visible for files from another source, such as an email attachment.
  • Hit the Apply button and then, click Finish to close the window.