Ok, I just for the hell of it re-enabled the plugin that Erwin said to disable and the error message went away.

Now I'm wondering though, Erwin said the subscription goes to the buyer not the person it's intended for. I guess I could setup a paypal developer account and test this out but I haven't looked into that yet.

haha
Has anyone else experienced the problem that Erwin was having? I am running 3.5.4 as well, but like I said re-enabling the plugin that Erwin said to disable got rid of the above error message.