Excel Files saving in invalid file format

Question

I recently bought an Acer Switch 12 and installed Microsoft Office 2013 on it. 

Midway through last week, I've been encountering this error:

The error is not restricted to just the file above. It's been happening to most of the excel files I am constantly using, and I cannot determine the cause.

I have already run my antivirus, malware and spyware softwares, including Microsoft Safety Scanner, but the error still persists. I have had to restore my files several times already, to the point that any work I've done for a day sometimes get negated by the restoration. Can somebody help me with my problem?

Answer 1

@Kristine De Guzman,

The missing header was all it was lacking, after all.

The good news is that, this was easy (with the appropriate tool) to reconstruct it.

And the file is now fine for use in any Excel version.

I have uploaded it here : http://www.arstdesign.com/papers/2015\_GSN\_applicant\_tracker\_Copy.2.zip

(It's a 882 KB file. It's zipped that's why it's ten times smaller than yours)

Question is how to avoid this in the future. Answer begins by testing if this is a systematic problem in your current Excel 2013 install. You can answer the question by creating a trivial file.

Answer 2

Thanks Stephane.

The errors are actually consistently happening on old files that I have that are saved in the xls format. Most of them are simple databases I use for tracking my work. 

To date, I have not yet encountered the error again after I saved all my xls files to xlsx versions. I've had some formula and cell formatting changes when I saved to the xlsx version, though.

@James Cone

The file size went way down when I resaved to xlsx :D I now have to ensure all my colleagues can open xlsx files.

Answer 3

@Kristine De Guzman,

OK. If you have more such files you would like to fix, zip them and send them over to my email address (click on my profile icon).

Other than that, do me the favor to mark this thread as Answered. Thanks.