Hello and welcome to the community! 
That sounds pretty annoying.
Have you checked out this thread? It contains structured steps you can try to follow: I can’t Install WeMod / "There was a error installing the application" - #2 by Ravenfyre.
Note that adding a software to your antivirus after it potentially removed a part of the software doesn’t automatically recover anything that was deleted, so the steps need to be followed in that order.
There are also a couple other things mentioned there to check as well, besides your anti-virus. 