The very last script you have in your global header in Structure > Headers & Footers > Global Header & Footer is missing a closing </script> tag at the end. This is causing the Post Reactions plugin not to work.
When copying code to your forum always ensure you have the full code copied and aren't missing a part of it on accident.
“My ONE mistake... was making many mistakes.” - Vinny Pizzapasta
Plugins, template modifications, and codes! Everything I've created in one place: