Excel found unreadable content in XLSM file. Do you want to recover the contents of this workbook?

Excel found unreadable content in XLSM file

Our XLSM template file was generating report successfully when we tried with Mozilla Firefox and Google Chrome. When same Excel template was tested with Microsoft Internet Explorer, it was generating the report but below error was occurring while saving and opening the report. 

“Excel found unreadable content in 'xlsm' file. Do you want to recover the contents of this workbook? If you trust the source of this workbook, click Yes.”

On clicking Yes button, it popped up another message ‘Repairs to XLSM file’ with below text

Excel was able to open the file by repairing or removing the unreadable content.

Removed Feature: External formula reference from /xl/externalLinks/externalLink1.xml part (Cached values from external formula reference)

Click to view log file listing repairs C:\Users\<username>\AppData\Local\Temp\error051680_01.xml

The content of error051680_01.xml was as below

<?xml version="1.0" encoding="UTF-8" standalone="yes" ?>

- <recoveryLog xmlns="http://schemas.openxmlformats.org/spreadsheetml/2006/main">

<logFileName>error051680_01.xml</logFileName>

<summary>Errors were detected in file 'C:\Users\username\AppData\Local\Microsoft\Windows\Temporary Internet Files\Content.Outlook\D37RMGPB\FileName.xlsm'</summary>

- <removedFeatures summary="Following is a list of removed features:">

<removedFeature>Removed Feature: External formula reference from /xl/externalLinks/externalLink1.xml part (Cached values from external formula reference)</removedFeature>

</removedFeatures>

</recoveryLog>

Actually we were trying to generate Excel report based on XLSM template file. Internally the template data was populated by Aspose.Cells from Java side. We found that Internet Explorer behaves differently when compared with Firefox and Chrome in relation to runtime Excel 2007 report generation. 

The exact root cause for "Excel found unreadable content" was still unknown. It seems, when template was directly opened from website, template was opening by embedded within web browser and maintained references of dynamic Excel file name (created by Java) in temporary memory. On saving Excel report file to user machine, it used to save the file on user machine with some external reference (cached from temporary memory location of Internet Explorer).

Next we followed below process for "Excel found unreadable content" wherein the external references can be checked using below steps:

1. Change the saved file extension to .zip. For e.g. “FileName.zip”
2. Extract the zip file to a folder e.g. “FileName”
3. In this case, go to “\FileName\xl\externalLinks” folder. It shows XML files related to external references.
4. In this case, “\FileName\xl\externalLinks\_rels\externalLink1.xml.rels file show external reference to the Excel file at temp location
5. File “\FileName\xl\externalLinks\externalLink1.xml shows references to some external links

This all was very confusing and underlying root cause for "Excel found unreadable content" was still unknown.  Based on Microsoft forum input, we tried enabling VBA component in Microsoft Office and again checked the “unreadable content error” issue. But the issue didn’t fixed. Only good thing at that instance, we felt there was compilation error issue which sometimes unnecessarily occur.

Microsoft Support team instructions on Excel found unreadable content issue.

 

Finally, we had to contact Microsoft engineer to look into this. Initially he advised to run Microsoft Support Diagnostic Tool packages which is available for below operating systems

Windows XP (x86 and x64)

Windows Server 2003 (x86 and x64)

Windows Vista (x86 and x64)

Windows Server 2008 (x86 and x64)

Windows 7 (x86 and x64)

Windows Server 2008 R2 (x64)

Windows 8 (x86 and x64)

Windows Server 2012

For frequently asked questions about diagnostic data collection and uploading tools, Microsoft advised to click the below link.

http://support.microsoft.com/kb/2598970

However all these steps didn’t resolved the issue.

Finally Microsoft engineer advised to send sample copy of our Excel template to investigate further on this. Later on he mentioned that the problem seems to be with the sheet name with the Excel template. Actually one of the sheet name has more than 31 characters. We reduced the sheet name to less than 31 characters which luckily addressed the issue in our situation!

Hope this article detail might have given you some insights what scenarios we went through and reactive steps we followed. Thanks for reading our content on the issue of "Excel found unreadable content in XLSM file".