Hi KHearty
Thank you for your post, I'd like to extend you a warm welcome to the Community Forum, I hope you find it a valuable resource.
Generally, this error is related to the number of characters in the Notes field and impacts saving the changes to the other fields in the client's card if characters exceed the maximum limit.
May I know where exactly you are trying to change the address? Can you please provide more details on how you changed the address details?
Looking forward to your response to be able to help you with your concern.
Best Regards,
Cel