Error: "Unhandled promise rejection"

[akai-hana]

I'm unsure why this isn't working. Below I attach the error it throws, which I couldn't find anywhere else:

[arRPC > ipc] listening at /run/user/1000/discord-ipc-0
[arRPC > websocket] listening on 6463
[arRPC > process] started
[arRPC > ipc] new connection!
(node:20447) UnhandledPromiseRejectionWarning: TypeError: Cannot read properties of undefined (reading 'handleEvent')
(node:20447) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). To terminate the node process on unhandled promise rejection, use the CLI flag `--unhandled-rejections=strict` (see https://nodejs.org/api/cli.html#cli_unhandled_rejections_mode). (rejection id: 1)