Built-in page and post slugs error

This my first day with MetaBox.
I migrated from Toolset and I get the following errors.

Opening the admin Post Types menu item, I get for the Pages slug (which is: page):
ERROR: the slug must not be one of WordPress reserved terms.
Same error for Posts slug (which is: post).

The slugs should be correct. Am I supposed to change them?

Thank you.