The file format is invalid error

Nowadays, the Spreadsheet program is popularly used to perform the calculation, integrate information from different applications and analyze the data. Excel is a widely used application and used in various official workplaces. The user can easily maintain separate worksheet for individual drafts of any works, complex and multiple calculation are done in just one click and statistical representations of work can be perfectly shown in different diagrammatic forms.

But apart from its popularity and advancement, there are cases seen when the Excel file gets corrupted and start showing errors. Here in this article, we have another Excel error:

 “.XLS file format is invalid” error

Here get the complete information about the error XLS file format is not valid as well as how to fix it easily. But before moving further let describe it best with the user experience:

I keep having a problem while saving a particular .xls excel 2007 file. It is also being saved in 2003 compatible file format. When I attempt to re-open the file after saving I get the message “fileName”.xls File format is not valid. When I press Control shift & I, I get the error code 100109 displayed.

I cannot locate the error code shown so I am at a loss as of where to go from here other than recreating the file again, has anybody any clues as to the error code and how to correct as I get this problem about once a month. Thanks in advance!!!

                                                                                                  Original Post from Microsoft Community


What is “.XLS File Format is Invalid” Error?


The file format is invalid error keeps haunting the excel users. The appearance of this error can easily be recognized when the concerned XLS file doesn’t open. Each time when the user tries to open XLS file format, they will get a dialog box pops-up branding “.XLS file format is invalid” error.

This clearly indicates that the concerned excel XLS file extension is not recognized by the software and therefore it is declared as invalid. It is very irritating and the recovery of the original file format is almost impossible.

Well, this error is not limited to earlier Excel version the Excel 2016 users are also encountering “XLS file format is not valid Excel 2016 error”


Causes of the Excel Error File Format is Not Valid:


Well the error message is faced by the users when:

  • The file is not compatible with the version of the Excel you are using 
  • Or in the case when the file got corrupted


Fix Excel Error “The File Format is Invalid” Manually:


To deal with the XLS file format is not valid error here follow the manual solution to rectify this error message and regain access to your excel sheet.


#1 Change Excel File Extension:


Firstly you need to change the File Extension of Your Excel Sheet. Sometimes, the problem occurs due to the unsupported file extension of your excel file. To check the support of XLSX extension follows the step:

  • Go to  My Computer > browse Tools > Folder Options > File Types.
  • Make sure that the ‘XLSX’ extension is included there or not.
  • If not then rename this file and change ‘.xlsx’ to ‘.xls’.

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#2 Use Open and Repair Inbuilt Utility:


If the above-given workaround won’t help you to fix the error, the make use of the inbuilt Open and Repair utility. 

  1. Open the Excel workbook > go to File > Open option.
  2. Choose the file which you want to open but don’t make double click on it.
  3. After that go to the ‘Open’ dialog box > select ‘Open and Repair‘ option from there. This process will fix the corrupt excel
  4. Now check the error is fixed or not.

Well in some case it is found this inbuilt utility fails to repair the severely damaged file or errors so it might happen that still the error is not fixed.  Then, in this case, you need to make use of the third party repair tool to fix the error automatically and recover data.

Alternate Solution: MS Excel Repair Tool


You can make use of the professional recommended MS Excel Repair Tool. This is a special tool specifically designed to repair any sort of issues, corrupted, damaged and errors in the excel files so that one can easily continue to work in that file. It can easily restore all corrupt excel file and also recover everything which includes cell comments, charts, worksheet properties and other related data. The corrupted excel file can be restored to a new blank excel file. It has the ability to recover the complete data from the file and restore them even without modifying original formatting.

Excel Repair for Windows


Steps to Utilize MS Excel Repair Tool:





Hope in this article you get the complete answer to your query related to the “.XLS file format is invalid” error. Here we have tried our best to provide the reliable solution to fix the error. If the manual solution won’t work to fix the error.  Then, in this case, you can make use of the automatic solution to get rid of The file format is an invalid error.

Good Luck!!!  

Resolve “Invalid XLS File Format” Excel Error On Windows OS
Resolve “Invalid XLS File Format” Excel Error On Windows OS
Article Name
Resolve “Invalid XLS File Format” Excel Error On Windows OS
To fix the .xls file format in invalid error here follow the best solution like change the file extension and much more to fix the error and recovers the entire data…
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Repair MS Excel
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