A bug I found that may or may not be related to the current broken script error message at the top is when Sonic tries to grab Bowser when he isn't directly on top of the tail, he'll spindash ever so slightly into the air from the ground as if he jumped and did an aerial spin dash forward (without ever pressing jump, to be clear). This prevents the tail from being grabbed for the rest of the fight, and you have to reset the fight via death. In the video, I grab with Mario to show it works, then grab with Sonic right on top of his tail to show that he can grab it too. I then spin dash towards Bowser's tail from a further distance twice (I fail the first time, then do it correctly the second time at the 27 second mark). After this, his tail cannot be grabbed by any character for the rest of the fight. If I'm just an idiot or made a mistake, please just let me know since I only started playing sm64coopdx the other day. Pretty sure this is related to this mod though from the testing I did though.