Page not found when granting permission

I followed the instructions to setup the Google credential and when I tried to grant permission, it would allow me login but then was redirected to an empty page with a message of Page not found. The redirect link ends with the following:
…. scope=https://www.googleapis.com/auth/drive.readonly
I tried another plugin (Google Drive Embedder) which has a different “Authorised redirect URI” and it was able to access the same Google Drive. Please let me know what my options are … thanks