********************************************************************************************************************I have found a NEW Temporary solution to this issue. So the problem in the error message box is something that tmpLauncher.tmp can't be moved to Minecraft.exe, error code 5. What I did was copied out from the tmp folder, the tmpLauncher.tmp file, and pasted it into the Minecraft folder, and everything worked after that. I DID NOT copy into .minecraft. I created a folder in the Downloads folder, and I named that folder, Minecraft. So all the work I have been doing, is within that folder, and not the .minecraft folder. It looks like all the .minecraft folder does, is holds your saves, resource packs and mods mostly.
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Below is my original message. Before I found the new temporary fix for this issue.

Just last night and the couple of days before today which is June 13th 2017, I was playing the newest Minecraft version, 1.12 here on the computer. So as of late, the Minecraft Updater runs, it gives a message that it can't complete or whatever, and error code 5.

There is a temporary fix, to take the .tmp file rename it to Minecraft.exe and then make a new folder called Minecraft, put the renamed .exe file in the new Minecraft folder, and it works.

Every now and then, the Updater runs for unknown reasons, and again gives an error code 5 message. So, in order to fix THIS issue, I take the file I renamed from .tmp to Minecraft.exe, copy it over the existing .exe file in the new Minecraft folder I had made previously, and everything works.

This temporary fix for getting around the Updater issue, is now, 100% broken and is not working at all to get the game working.

MOJANG: IF YOU GUYS READ THESE BUG REPORTS, AT THE MOMENT I CAN NOT PLAY MINECRAFT. Your new launcher is broken. It is EXTREMELY frustrating as I spent money on your product that seems broken.

Is there ANY motivation to get this issue fixed or not?? Didn't know I was paying for and supporting products that work one minute and don't work the next.