Take care not to include this block in itself, either directly or indirectly. For example, a page to page circle of parent areas and/or stacks and/or global areas, and thus create an infinite recursion.
If left unchecked, such a loop would slowly eat up all a web server's cpu and memory until none is left and the page fails.
Parent Area includes a catch for this and will throw an exception if too many attempts to render a Parent Area block are made when a page is shown.
Error: maximum Parent Area count of "11" exceededs limit of "10". Have you created a recursive chain of ancestors and/or stacks and/or global areas?
To correct the problem, you need to revert the page that created the loop to a previous version. The responsible page may be the page that shows the exception, or the parent or another ancestor of that page. If the execption prevents you from navigating to the page directly, you should be able to revert to a previous version via the dashboard sitemap.
If you add a large number of Parent Area blocks to any one page, the recursion error exception may be triggered when it should not have.
The counter for this exception is checked against PARENT_AREA_USE_LIMIT.
You can override this by defining a constant in config/site.php or by directly editing the Config table of the database using a database tool such as phpMyAdmin. Setting the limit to -1 will disable it completely (only advised for expert developers).