Hey @thecelinette,
I was able to log in and see the Error message when saving the page. Though the message displays, my changes are still being saved by the page. Be advised that this issue only happens on that particular page. I created another test page, and I could not replicate the issue, by the way. It could mean that you have added something that is incorrect on the page, which has triggered the Error message. I just do not know where or what it is. For now, to save you time, please do your changes on the mentioned page. It should be saved even if you are seeing the error message. I feel positive about this because I am sure that you will see the Section I have added as proof. Please check the page now.
Thanks.