In Qlikview there is a hard timeout for the thread copying a document log to the shared log folder, after a task reload is completed. This timeout is set to one minute.
Environment
Qlikview 12.00, 12.10, 12.20, 12.30, 12.40, 12.50
Resolution
Upgrade to Qlikview 12.50 SR 4 and add the hidden setting:
One Minute is the default, if you still have issues you can extend the value further.
Workaround if you don't upgrade:
Take some stress off the disks so the file can copy within a minute. An example would be if the log folder is located on the same disk as the source document folder, move the log folder to a different disk.
If possible break down the task to more sub tasks to be able to get the log copied.