You know those errors that you just can't seem to find the answer to, no matter how much you peruse Google? This was one of them. I use an Excel macro that takes some entered information, and then e-mails it to a specific list of individuals. While this script has worked time and time again, and the code hasn't been altered in any way, it suddenly quit working. I kept getting a "Runtime Error: No such interface supported." message.
After clicking the "Debug" button, I was brought to this section of code. As I mentioned earlier, nothing had changed in the code, so I knew there was nothing wrong with this snippet.
Anyway, long story short, after much trial and error, I remembered that we had recently installed "Skype for Business 2016" on some of the machines.
I could've done a little more troubleshooting as to why this prevented the script from working, but I was too lazy. It fixed it, and that's all that mattered. Anyway, the point of all of this is to hopefully save others time from having to pull their hair out trying to fix the same issue I had.