Facebook error: “Cannot redirect to Facebook”

Google error: “Error: redirect_uri_mismatch”

Similar error may occur when using other ID service providers.

This error occurs when your ID Service provider is expecting to be reached via HTTPS but your app is calling it in HTTP.
Try one of following to fix the problem:
a.    Deploy your DataPage in HTTPS.
b.    Or configure your ID Service to accept HTTP.

Configuring your ID Service is explained here. Step 8 shows how to do this in Facebook.