The action cannot be completed a this time

you can directly do it on phone instead on sending invitation link.. just select the invite in person and follow prompts

Sounds like an Apple server problem.

If necessary, there is a contact link.

Apple ID Support

Apple ID Support (2)

Apple Support by e-mail or chat Select your device, Battery, Power and Charging, then Power adapter not working to get a chat option. If you need to talk to them, ask them if they will do a Skype or FaceTime with you.

Apple Support using Twitter

Or fill out and submit this form.