Thank you Kwartet, I will give that a try and let you know if that fixes the issue.
And thank you craigb as well...to be honest, I have never used Sandbox - I am new to the Avast security and don't know how to open things in sandbox. When I first got that pop-up message, I actually chose "open in Sandbox" just to see what would happen and nothing did so when I tried to install again I then chose "open normally"....but that didn't work either as I mentioned in my original post and I just didn't bother mentioning I tried the Sandbox option. I'll go look at the auto sandbox feature and see what I have it set to.
Edit to add: ok, I followed your instructions Kwartet but I am not sure if I need to have all three R, W, X checked for this? There are already some file paths in this list (I assume automatically placed there as I didn't put them there) and none of them have X chosen, so I wasn't sure what to do for the Wildtangent Games. I left all three checked for now, but let me know if that is necessary. Thanks!
Second Edit to add: Success! The game downloaded and installed with no issues.
Thank you!!! Let me know what to do about the R, W, X exclusion choices for this though, thanks.