Re-installation problem, Hung up on "verifying Anki" (Mac)

So I did something silly. After not having used Anki last semester, I needed to use it again this semester. When I opened it, I got the message saying an update was available. Having forgotten that I can’t use the updated version because my computer is too old to support the latest OSX, I downloaded the new one and… it didn’t work. Then I realized what I had done and tried to re-install the original (I still had the originally dmg) Every time I do, it gets hung up on the “verifying Anki” window when I try to open it after installation.
I have a feeling there is something else I need to do to fully uninstall the previous version, but I’m not sure what it is. HELP!

The download site links to 2.1.35-alternate, which should work on your machine. If you continue to have problems with verifying, restarting your machine may help.