VC2095: System block has changed since this override was made

The built-in version of this system block has gained parameters or slots since this customization was made from it. The customization still works; pages just can't use what's new on this site.

How to fix

Compare the customization with the system block's default and add the new parameters or slots. Customizing it again from the default (Reset to default, then Customize) also clears this, but loses your changes.