Devs were checking the possible problems and checked the format of client storing. In 99.99% of cases "Bytes Per Sector" number is 512. And accordingly, if client is downloaded from the Torrent, it's stored in that format and when launcher or game is trying to open it, it can't be read in such format on your PC, as on your PC it's 4096. Due to it both client and launcher think that something is broken and start the re-download process.
If you want for the download to work properly you need to change Bytes Per Sector format to 512. Otherwise, you need to wait for the change on our side. We are working on the launcher modification for a while already, that will let you to correct the Bytes Per Sector structure without client re-download.