Hello,
I'm trying to add lens flare with this free lens flare pack https://blendswap.com/blend/13733 by Carl Irwin, and there is even a tutorial on Youtube https://www.youtube.com/watch?v=Wf5wHXZ6CJU&t=795s&ab_channel=cfirwin3, but I have no idea how to make it work.
Help would be appreciated. Thank you.
That is pretty old, it uses Blender Internal Renderer and that is no longer used since 2.80.
You'd need to Download Blender 2.79 to make that work:
