when you go to a new page by the following command

onTap: (() => context.go("/secondPage"))

the router removes the previous destination and overlays the requested destination. that is why when you pop this destination. You are receiving an error. However when you go to new page using the following command.

onTap: (() => context.push("/secondPage"))

the previous page is still left on the stack and popping the new page exposes the previous page.