Side Bar (Deleting and Inserting a new page)

Greetings all, I have encountered an issue while trying to remove a page under the sidebar and adding a page.

The first photo is my issue as I was trying to remove the LIST PAGE and insert a new ABOUT PAGE but I can’t save the project, it says the app.routing.module.ts file can’t be saved due to new content.

The second picture is an illustration on me trying to remove the LIST PAGE and add ABOUT PAGE.

Please assist. Appreciate a lot.

If you could place the code and in which framework you are programming, we could help you in a better way since blindly it is a bit difficult. regards

Oh dear, I forgot to attached the photo, so sorry. Here you go: