It all depends what run out of free space, temp directory od download directory. If download directory(drive) runs out of free space or hits free space limit you've set it stops decoding, but continues to download to temp. FIles are not removed from queue cause they're not decoded. So, free some space on download location (to be over free space value) and decoding will resume. Or just exit and enter program and if there is enough free space decoder thread will decode all downloaded files from download queue.
This is all for >=0.25.0 version