[kubuntu] USB error when flashing Zenfone using xFSTK Downloader

I am getting the following error when using this program.

23:00:28 - XFSTK-LOG--USBSN:7FB7B021FE47F499--USB I/O ERROR RETRYING R/W
23:00:28 - XFSTK-LOG--USBSN:7FB7B021FE47F499--LogError
23:00:28 - XFSTK-STATUS--USBSN:7FB7B021FE47F499--Error Code: 4 - Error attempting to read ACK/NACK from IN Pipe
23:00:28 - XFSTK-STATUS--USBSN:7FB7B021FE47F499--Unknown Ack code:0, aborting ...
23:00:28 - XFSTK-LOG--USBSN:7FB7B021FE47F499--void CloverviewPlusDownloader::do_abort()
23:00:28 - XFSTK-LOG--USBSN:7FB7B021FE47F499--virtual bool CloverviewPlusUSB20Device::Abort()
23:00:28 - XFSTK-STATUS--USBSN:7FB7B021FE47F499--FAIL
23:00:28 - XFSTK-STATUS--USBSN:7FB7B021FE47F499--Errors encounter during OS download. Aborting ...

In Windows 7 it produce similar error too " USB bulk read fails.

Looking at both, I guess it got something to do with USB, but I can't figure out on how to solve this. The full text file is attached

Please help.