I am a fan of Portal so when I saw that you could make a portal gun it was the first thing I set out to do on the server. then when I get it, the gun won't shoot portals it picks up blocks just fine, it makes a noise when you hit the reset portal button, it makes a sound effect when you shoot it, but portals are not made. even more is that when I tested it in single-player, it worked no problem. I have seen people suggest that optifine interferes with it but I am not using optifine. I have tried using the fuel source but nothing works. if anyone has had the same problem and knows what to do., please message me.