So found the issue. Proxy settings of the OS have caused that the download files had 500Bytes having content of the proxy error message. It also explains why the download speed of the mods has been reported as 2048MB/s. After correcting proxy config, everything is just fine. I propose to add to log sizes of the downloaded files and also veryfication, that the file downloaded is really an archive. Its wierd that the logs does not show any errors during archives extract, that were purce text files :)
Thanks for suppot and cheers :)