File in different format than specified by file extension.


After exporting the version history, the resulting file is named 'listname.xls' however, when Excel tries to open the file, it complains that "The file you are trying to open, 'listname.xls', is in a different format than specified by the file extension."

The file can still be opened, but users are faced with this warning. Can this be resolved?

Paul Wentink


nadeemyousuf wrote Apr 18, 2014 at 7:47 AM

Hi Paul,

You are constantly getting that warning message because the file that got created is not an actual excel file. If you will look into the generated file, it's just a bunch of html tags
See this for reference

The code is available for the download, so if you can't do without getting the rid of warning then you may need to use ClosedXml