Issue Summary

Back in a day, when we were creating pages in a space that already have a page with the same title, Confluence would pop-up us a message clarifying this.
Nowadays, it seems it is only throwing a general error message.

Steps to Reproduce

1. Create a page and name is as "Test Page";
2. Publish it;
3. Create a new page and name it as "Test Page";
4. Try to publish it.

Expected Results

An error message saying that a page with that title already exists will be shown.

Actual Results

A generic message is shown on the screen saying:
Your work is safe, but there's an issue.
Refresh the page, and click Publish again

Identifying the scenario you are dealing with

1. Open the browser developer console, and click over the Network tab;
2. After that, hit the Publish button again;
3. A red text will appear, click there;
4. Open the Response tab;
5. Locate this piece of text: A page with this title already exists

In case you located it, follow the below workaround.
In case you didn't, raise a new support ticket to us mentioning this bug request, the page you are facing this issue, and the data access approved in the ticket.

Workaround

After identifying the this is the case, change the page's title and then publish it.