the folder, to which I was referring, is the folder where you saved
the downloaded program;
this is the last thing to close before installing the program.
Sounds as if you downloaded/partially downloaded a corrupted file
for whatever reason;
delete.
Then re-download the program -
and while it is downloading - saved to wherever (as the Download
folder) - do not use your machine;
take a break for those few minutes.
For the same(?) reason programs like to be alone when installing,
they tend to download better that way as well
Hoping this helps,