I solved it about an hour ago by running "make clean".
Just needed to get some sleep. Woke up this morning and realized I'd seen a similar issue when compiling a media player I wrote a few years ago that I wrote in C++ using VS2015, but wrote for multiple platforms. I remembered spending hours going through options, searching the web, and rebuilding repeatedly. Then, I realized I had turned off the option to clean before build. I turned it back on and my code compiled just fine.
I looked up how to clean the configuration output using make (yes, there was a facepalm involved), ran the clean command, and I now have a working UI Simulator.
Thank you for your assistance.
P.S. May want to add that to the build wiki