IE/Edge Browsers - Cannot decode a malformed JWT

We have recently upgraded our authentication flow to use OIDC compliance. After doing so and following the new tutorial:

Authentication no longer works for IE or the Edge browsers. It fails when a call to parseHash in the handleAuthentication method is made. The parseHash method returns an error: "invalid-token" with the description "Cannot decode a malformed JWT". Anyone have any idea what might be going on here?