useOperation: Cannot read property 'apply' of undefined

We have a simple React app, brand new, doesn't do anything but attempt to invoke a single API and dump the contents of the return data, as a first attempt to use this package. I own the API project too, and I can see the request which returns the OpenAPI doc (and I know it's valid, I've used .NET and Java codegen to call it). I'm not sure where or how to troubleshoot this error message.

After the OpenAPI doc is returned, the call to useOperation fails with:

TypeError: Cannot read property 'apply' of undefined
        at useOperation.js:63
        at step (useOperation.js:33)
        at Object.next (useOperation.js:14)
        at fulfilled (useOperation.js:5)

The OpenAPI JSON is v3.0.1 and it currently has just a single entry in paths:

"paths":
  "/techsupport/CacheSystem/GetNavData": {
    "get": {
(usual stuff omitted: tags array, response 200, content list, etc.)
  }

This is on a locked-down corporate machine (no Internet access etc) but the code is so simple I'll just retype it here. It's Root instead of App because the real React apps are part of a single-spa parent app:

const Root = (props) => (
  <OpenAPIProvider definition="https://localhost:5050/openapi/v1/btpapi.json">
    <DumpNavData userData={props.userData} />
  </OpenAPIProvider>
);

const DumpNavData = (props) => {
  const { loading, data, error } = useOperation('/techsupport/CacheSystem/GetNavData', props.userData.viewEntitlement);

  if (loading) {
    return <div>Loading</div>;
  }

  if (error ) {
    console.log(error);
    return <div>Error</div>;
  }

  const stringData = JSON.stringify(data);

  return <div>{stringData}</div>;
};

export default Root;

anttiviljami / react-openapi-client

useOperation: Cannot read property 'apply' of undefined #10