Hmmm.... the fact that this is a server-side error makes me inclined to think that it's not your plugin causing the problem. At least, it's not one I've seen occur before! I would check the following if you're able:\n1. You browser's console logs for any interesting errors/warnings \n2. Your browser console's "Network" tab (assuming chrome) to see if you get any additional details in the error response from the server\n3. Your server logs (assuming you're running it locally) to see if the request throws any visible errors there.\n<@UMTM37Q64> <@UH0UPCJVD> have you encountered a 405 like this in the wild?