All vanilla client queries fail with 500. Setup problem?

const useCreateRandomWorker = (): ReturnType => {

    const [isCreating, setIsCreating] = useState(false);

    const createWorker = async (): Promise<Worker> => {

        setIsCreating(true);

        const randomWorker: CreateWorker = await client.generateRandomWorker.query(null);

        const createdWorker: Worker = await client.createWorker.mutate(randomWorker);

        setIsCreating(false);

        return createdWorker;
    }

    return { createWorker, isCreating };

}

export const WorkerRouter = router({
  generateRandomWorker: procedure
        .input(z.null()) // <---- I have tried completely omitting `.input` and with a `null` property
        .output(PrismaWorkerCreateInputSchema)
        .query(() => WorkerService.generateRandomWorker()),
  getAllWorkers: procedure
        .input(z.null())
        .output(z.array(WorkerSchema))
        .query(async () => await WorkerService.getAllWorkers()),
  createWorker: procedure
        .input(PrismaWorkerCreateInputSchema)
        .output(WorkerSchema)
        .mutation(async ({ input }) => await WorkerService.createWorker(input)),
});