“Notability” is damaged and can’t be opened.

I am using Mac OS Mojave 10.14

I just downloaded notability from the app store and I am getting this error every time I try to open it.

“Notability” is damaged and can’t be opened. Delete “Notability” and download it again from the App Store.

I tried setting security to accept all apps, left click open, uninstall and redownload from app store, why am I getting this error I need to look over my notes for a test Monday.