The solution is to have the same keys on both machines.
I have two computers with the admin console.
Each has a different key, which is why I couldn't install the packages on another machine with a different key.
So I retrieved the key from one of the machines to install it on the other...

Hello,
I'm unable to install packages on the machines where the WAPT agent has been deployed.
In the admin console, I can add packages to the machines, but when I apply the updates, the packages show errors. I also have a package that is being added with an error, which corresponds to...