I checked it now and that rule got deleted from the system. When tried to delete it, it was thrown that error message.
But still the deleted rule (Rule-OBJ-HTML @baseclass xyz) is picked instead of latest rule.
Customized pega Login Page and done some changes as part of our requirement in that HTML rule and checked in. The latest version of the rule is not picked, when traced unauthenticated browser session. (before login).
checked Operator profile and unauthenticated version (01-02) is available. Still the deleted version is picking and if clicked on it in tracer not able to open the instance. Please find the attachment and let me know .