Okay, I figured out the problem. I am posting it here just in case someone else experiences the same type of problem, the possibility being probably slim to none. It was caused by the receiver for my Microsoft Xbox Elite controller. The receiver was plugged into one of my computer's USB ports. It was showing up in my Device Manager in the Network Adapters section. It indicated that it was disconnected, which I figured was because the controller was turned off. Anyways, after trying most everything else I could think of, I finally tried unplugging the receiver. I then opened HomeManage and was able to activate it online without any problem.
Thanks to the admin for responding to my post so quickly. This is easily one of my most used programs. I am happy and relieved to have it back in use again.