Hi Szymon,
yes I'm able to extract the XMl file and only upload that one, but that means that all constants point to a file that's not there resulting in gibberish for all labels and the internationalization is gone, since the language-dependent property files are also missing. So this is not a feasible workaround for me.
Unfortunately, I have no working examples. Even when I download one of the zipped standard archives and try to re-upload it untouched, the error occurs. So unless the parser tells me in a more detailed way than "unable to read file", what the problem is, I'll never find out..
>>I understand that at this moment you are trying to upload the file which you use for NW 7.02?
No. I'm trying to upload a file to a portal that's on 7.31. Back when the portal was still on 7.02 I had a similar problem which, however, I was able to solve (back then I had messed up the folder structure).
Cheers, Lukas