Hey there, sorry to hear you’ve been stuck on this for two days—let’s dive into targeted fixes to get that critical SpreadsheetML file open in your LibreOffice 5.4.4.2 deployment. Since other documents work fine, the issue is almost certainly tied to this specific file’s XML structure or compatibility quirks with your older LibreOffice version.

Quick Compatibility Tweak #

First, let’s rule out a simple setting mismatch:

• Go to Tools > Options > LibreOffice Calc > Compatibility
• Check the box labeled "Use Excel 2003 compatibility" (the exact wording might be slightly different in 5.4.4.2)
• Restart LibreOffice and try opening the file again. Legacy XMLSS files often require explicit compatibility flags to parse correctly.

Validate and Repair the XML Structure #

Since this is an XML-based file, even tiny syntax errors can break opening. Let’s dig into the code:

1. Rename the file from .xls to .xml so you can edit it in a text editor like Notepad++ or VS Code.
2. Use the editor’s built-in XML validator (or install an extension) to check for:
   • Missing or mismatched closing tags
   • Conflicting namespace declarations (your header has duplicate urn:schemas-microsoft-com:office:Spreadsheet entries—try removing one of these duplicate lines)
   • Encoding inconsistencies (ensure the file stays in ISO-8859-1; don’t let the editor convert it to UTF-8 when saving)
3. After fixing any errors, save as .xml, rename back to .xls, and test opening again.

Test with a Newer LibreOffice Version (Temporarily) #

Your 5.4.4.2 is from 2018, and newer LibreOffice releases have significantly improved support for legacy Microsoft XML formats. If possible:

• Download a portable version of the latest LibreOffice (so you don’t disrupt your existing deployment)
• Try opening the file there. If it works, save it as a standard .ods or .xlsx, which should open seamlessly in your 5.4.4.2 instance.

Convert via Alternative Tools #

If you have access to Microsoft Excel (even a trial), open the file there and save it as a standard binary .xls or .xlsx (not the XML Spreadsheet format). Excel handles its own legacy XML files best, and the converted version should play nice with LibreOffice.

Alternatively, use the ssconvert command-line tool included with LibreOffice to batch-convert the file:

ssconvert your-file.xls converted-file.ods

Run this from a terminal where LibreOffice is installed, then check if the ODS file opens in your 5.4.4.2 setup.

Check for Hidden Header Corruption #

Your file’s opening lines have two processing instructions:

Sometimes extra whitespace, unprintable characters, or the <?mso-application...?> line itself can throw off LibreOffice’s parser. Try:

• Opening the file in a hex editor to check for non-ISO-8859-1 characters at the start
• Removing the <?mso-application progid="Excel.Sheet"?> line entirely, saving, renaming back to .xls, and testing again.

内容的提问来源于stack exchange，提问作者alara