5.0.5 file lock issue

[V8Driver]

rather annoying, don't want to expose methods and procedures but let's say a friendly party is hosting an .mkv file which is torrented? and if I downloaded it using qbt, any version but this, ie 5.0.5, I could set it to download first and last, and consecutive, and start watching it, and it would finish downloading, typically, before, the media finished? now I get a file lock, so qbt errors out 'file in use?' and the file is hard locked through the OS so restarting qbt, etc, etc will not release the lock, I did not dig in on the windows side, so I cant give cacls etc; however, deleting the file and re adding the torrent was my preferred fix, I didn't try relocating it etc, that's why I am posting here! thanks.