Need help with setuperr.log on failed upgrades to Build 10586

Since I installed Win 10 Build 10240 a few months ago Windows Update has been trying on an almost daily basis to upgrade it to the current Build 10586. While all other updates seem to have installed normally, this one has consistently failed. Yesterday I tried a manual upgrade using a DVD of the downloaded Build 10586. I turned off Windows Defender and Windows Firewall and ran Setup from the DVD as Administrator. But it failed during the initial Installing Windows phase at roughly the 18% mark, leaving what has to be the most useless message Microsoft has ever come up with: "Something happened--Windows 10 installation has failed". I looked at setuperr.log but am not able to decipher what may have happened. I've attached that log; can anyone come up with a reason the installation failed and what I might be able to do about it? (I realize that I could probably do a clean install of Build 10586 but would prefer to do the upgrade if possible.)

Thanks for looking at the error log. There were so many supposed "errors" listed that I had no idea which were temporary and resolved and which were fatal.

There is no SafeOS subfolder and thus no winre.wim file under Sources; the three subfolders of Sources remaining after the upgrade attempt are Diagnostics, Panther and Rollback. However, is it possible that the SafeOS subfolder existed during the attempted upgrade and was deleted in the cleanup after the failure? If it should be there before and after after the upgrade, what would be the possible cause of its absence? Is there some way I can create or copy it there before another attempt?

As for AV and Firewall, both are the built-in Windows components, and both were disabled for the attempt.

Thanks for the tip. While it didn't directly solve my problem it did give me a lead which resulted in a solution.

I looked at the post by Rahul_compfreak you suggested. There was no entry under the Registry key he named. But the gist of your replies was that there was a problem with mounted images. So I Googled a bit and found:

Unmount and Clean up a Wim Image using DISM

which gave me guidance on dealing with such problems. My first check with DISM told me the mount status was Invalid and pointed to a mount directory in the Recycle Bin and an image file C:\$Windows.~BT\Sources\SafeOS\winre.wim, exactly the file you told me to look for in your first reply. So I used DISM to clean up the mount status and tried the upgrade again. This time it went successfully.