I hate that with Sid Meier's Railroad after upgrading to El Capitan. Couldn't do nothing until the app or whatever was updated.
Well this is a little different.
This is: if the App was pre-MacApp Store, before certificates, AND any developers who don't want to sign up for a certificate, it's pretty much DEAD. BUT I think Apple has a secret list of some sort, for some let's just say, "whitelisted" companies. Because, I have gotten some pre-MacApp Store to work, but they are like Adobe Level.
It's a little tricky... just put it this way Y'ALL have been warned...
Basically in a NUT SHELL
You will have to "JAILBREAK" YOUR MAC. Trust me... but you'll still get to be like a regular Mac vs iPhones...
I am going to ADD THIS:
this link:
http://www.iphonehacks.com/2016/09/fix-macos-sierra-problems.html
Supposedly has a better fix, for if you can't upgrade the app, but it's mainly like you have to upgrade that app.
But here is the thing, you download some old app off of a site, and it gives you this App is Damaged, then you have to go thru this whole cache clearing p-ram zap fix BS for EACH APP you just one day download, and get a warning? WOW that's gonna suck, how much?
I don't even want to restart my MacPro right now and I don't want to P-RAM Zap etc to get the App, I have just been trashing them or the dmg...
But I guess if you need the App bad enough you'll try this every time if it works...
Good Luck...