Could not unzip extension

If you are trying to install a Google Chrome extension/.CRX-file in Windows, 
and receive this error:

Det gick inte att installera tillägget

Paketet är ogiltigt. Information: Could not unzip extension.

OK   

Then it's likely to think that the extension has been packed in Google Chrome on Linux.

Extensions packed in Google Chrome on Linux does not seem to work on Windows machines.

The opposite works, Linux version of the browser can take Windows-packed extensions. 
So you may unpack the extension using Google Chrome in Linux, then repack it 
in Windows, then you may install.

If you are a developer you may use Windows version of Google Chrome to 
pack your extensions and not Linux as you ommit the Windows platform by doing so.

One note I made about this is the file size. Packing an extension in Linux made 
the .CRX file about 63 kB. Doing it in Windows made it about 38 kB. A wild guess 
is that the different platforms use diffent compressing methods/formats.

Windows clearly uses a modified .ZIP format, so what does then Linux use - .TAR.GZ?
Or is it just a special header or something?