Problem to add a extended setting

I’m trying to add a new extended setting (for example aaa.bbb.ccc=test) like the webMethods_Integration_Server_Administrators_Guide_6.1.pdf explains and when I click Save Changes
my property added did not automatically display a check mark in the Show
and Hide Keys list and was not displayed, with its value, in the Extended Settings list.


Settings are ignored that do not begin with a valid prefix.

If you add then it works.