How about, you take a chill pill. We aren’t here to help you at your beck and call, and if you can’t read a manual, that’s not our fault. OP asked why they were getting the BP error, I told them because it derived from a C++ class. The first link LITERALLY shows you how to do it AND provides a downloadable example.
If you don’t want to hear “READ THE MANUAL” game dev isn’t for you. A lot of us have spent YEARS learning this stuff and take time out of our lives to help people as well, and then ungrateful idiots come in and get mad BECAUSE THEY CAN’T READ A MANUAL.
And no, there won’t ever be a time that I would need help and be a snotty little child about it.
Also, why are you bringing up stuff from FIVE YEARS AGO? you can literally use the base shooter demo, use the project renamer tool on it, then migrate your current level across to it and hit play. Even a noob can do it now.