This worked for me.
I had the same problem, which I believe was caused by a program update not
rebooting automatically when finished and continuing to download car updates then
rebooting, so ending up with one version starting the download and then trying to
continue with the new version.
I fixed this by using ES file explorer to navigate to the scantool folder then downloads
and deleleting all the folders with part downloaded files.
This must not be done when the program has crashed but straight a reboot.
Then you can do the updates.
Use this info at your own risk