Warning: Undefined array key "oauth_token_expires" in /home/.sites/91/site807/web/wordpress/wp-content/plugins/photonic/Platforms/Google_Photos.php on line 924
 
Google Photos Refresh Token invalid. Please authenticate from Photonic → Authentication.
Error encountered during authentication: 
{
  "error": "invalid_grant",
  "error_description": "Bad Request"
}
See here for documentation.