I'm getting the same message and when I go to my program files (x86) -> Minecraft -> tmp, there's nothing in there unless I'm actually launching the minecraft. But when I'm launching the minecraft I see the tmpLauncher.tmp but I can't delete it or move it because it'll say "The action can't be completed because the file is open in Minecraft launcher." I got the "Problem moving C:/Program Files (x86)/Minecraft/tmp/tmpLauncher.tmp to MinecraftLauncher.exe with error code 5" message the other week but it fixed and now it came back. Idk what to do.
Just go to the File of your minecraft folder [Minecraftlauncher.exe this exists in the folder] go ahead and delete TMP folder and then open the launcher then let it download it automaticly. that Worked with me i was even looking for a solution.